Protein adsorption at the solid/liquid interface is of wide ranging importance in many different areas of science such as biomaterial design, the fate of nanoparticles and in the food industry. As a result, many studies have been undertaken with varying foci but there still remains a lack of agreement between many working in this field and fundamental questions regarding the adsorption of proteins at the solid/liquid interface. Neutron reflectivity is a powerful technique for probing the properties of adsorbed layers at interfaces due to its high structural resolution and the possibility of using isotopic substitution to distinguish between components of a mixture. In this work, neutron reflectivity has been used as the primary technique for the investigation of proteins adsorbed sequentially or from a binary mixture. Initially, the adsorption of four proteins (carbonic anhydrase II, lysozyme, human serum albumin and maltose binding protein) onto a clean silica surface was investigated which revealed the importance of electrostatic interactions and entropic contributions to the driving forces for adsorption. Most of the adsorbed layers were described by a 2-layer model with a thinner, denser layer adjacent to the surface and a thick, diffuse layer extending into the bulk solution. The presence of impurities is also shown to have a significant impact on the adsorption of HSA. A study of the HSA/myristic acid system shows that the presence of small amphiphiles can inhibit HSA adsorption and also remove a pre-adsorbed layer. A comparison was made between the protonated and deuterated forms of two proteins, HSA & MBP, showing the deuterated proteins to have a higher affinity for the surface with adsorption occurring in a 3:1 ratio when from a 1:1 mixture. Likewise, d-MBP displaced h-MBP more readily than vice versa in an investigation into the effect of incubation time on the properties of the protein layer. The extent of desorption into protein free buffer is not affected by incubation time but the extent to which d-MBP was displaced by h-MBP showed a clear trend of decreased exchange with increasing incubation time indicating an active exchange process was occurring. This was also observed to a lesser extent for the sequential adsorption of binary protein systems, HSA & LYS and HSA & MBP. When investigating binary protein mixtures the higher propensity for deuterated proteins to adsorb is observed. LYS dominates when adsorbed from a mixture with h-HSA but from a d-HSA & LYS mix both proteins were adsorbed. The marked difference between the adsorption characteristics of perdeuterated proteins and their protonated counterparts provides a good case study for testing the neutron reflectivity technique when investigating systems with more than one component. This thesis assesses the limitations of the methodology of contrast variation for investigating mixtures as well as using different solvent contrasts. A comparison of neutron reflectivity and dual polarisation interferometry (DPI) shows that the two techniques are similar and any small differences can be attributed to the small change in surface chemistry. This comparison also highlights the advantages of DPI; high throughput of samples and detailed information but the restriction to using a 1-layer model limits its use.

This thesis aims to investigate the possibility of developing spectroscopic techniques for trace gas detection, with particular emphasis on their applicability to breath analysis and medical diagnostics. Whilst key breath molecules such as methane and carbon dioxide will feature throughout this work, the focus of the research is on the detection of breath acetone, a molecule strongly linked with the diabetic condition. Preliminary studies into the suitability of cavity enhanced absorption spectroscopy (CEAS) for the analysis of breath are carried out on methane, a molecule found in varying quantities in breath depending on whether the subject is a methane-producer or not. A telecommunications near-infrared semiconductor diode laser (1.6 µm) is used with an optical cavity based detection system to probe transitions within the vibrational overtone of methane. Achieving a minimum detectable sensitivity of 600 ppb, the device is used to analyse the breath of 48 volunteers, identifying approximately one in three as methane producers. Following this, a second type of laser source, the novel and widely tunable Digital Supermode Distributed Bragg Reflector (DS-DBR) laser, is characterised and the first demonstration of its use in spectroscopy documented. Particular emphasis is given to its application to CEAS and to probing the transitions of the two Fermi resonance components of the CO_2 3ν_1 + ν_3 combination bands found within the spectral range (1.56 - 1.61 µm) of the laser, providing the means to determine accurate ^{13}CO_2/^{12}CO_2 ratios for use in the urea breath test. Not all molecules exhibit narrow, well-resolved ro-vibrational transitions and the next section of the thesis focuses on the detection of molecules, such as acetone, with broad, congested absorption features which are not readily discernible using narrowband laser sources. To provide the necessary specificity for these molecules, two types of broadband source, a Superluminescent Light Emitting Diode (SLED) and a Supercontinuum source (SC), both emitting over the 1.6 - 1.7 µm region, are used in the development of a series of broadband cavity enhanced absorption (BB-CEAS) spectrometers. The three broadband absorbers investigated here, butadiene, acetone and isoprene, all exhibit overtone and combination bands in this spectral region and direct absorption measurements are taken to determine absorption cross-sections for all three molecules. The first BB-CEAS spectrometer couples the SLED device with a dispersive monochromator, attaining a minimum detectable sensitivity of 6 x 10^{-8} cm^{-1}, which is further enhanced to 1.5 x 10^{-8} cm^{-1} on replacing the monochromator with a Fourier Transform interferometer. The spectral coverage is then extended to 1.5 - 1.7 µm by coupling the first SLED with a second device, providing a demonstration of simultaneous multiple species detection. Finally, a SC source is used to provide greater power and uniform spectral intensity, resulting in an improved minimum detectable sensitivity of 5 x 10^{-9} cm^{-1}, or 200 ppb, 400 ppb and 200 ppb for butadiene, acetone and isoprene respectively. This device is then applied to acetone-enriched breath samples; the resulting spectra are fitted with a simulation to return the acetone levels present in the breath-matrix. Following this, the development of a prototype breath acetone analyser, carried out at Oxford Medical Diagnostics Ltd. (OMD), is described. To fulfill the requirements of a compact and commercially-viable device, a diode laser-based system is used, which necessitates a thorough investigation into all possible sources of absorption level change. Most notably, this includes a study into the removal and negating of interfering species, such as water vapour, and to a lesser extent, methane. A novel solution is presented, utilising a water-removal device in conjunction with molecular sieve so that each breath sample generates its own background, which has allowed breath acetone levels to be measured within an uncertainty of 200 ppb. Spectroscopic detection then moves to the mid-infrared with the demonstration of a continuous wave 8 µm quantum cascade laser, which allows the larger absorption cross-sections associated with fundamental vibrational modes to be probed. Following the laser's characterisation using methane, including a wavelength modulation spectroscopy study, the low effective laser linewidth is utilised to resolve rotational structure in low pressure samples of pure acetone. Absorption cross-sections are determined before the sensitivity of the system is enhanced for the detection of dilute concentrations of acetone using two types of multipass cells, firstly a White cell and secondly a home-built Herriott cell. This allows an acetone minimum detectable absorption of 350 ppb and 20 ppb to be attained, respectively. Following this, an optical cavity is constructed and, on treating breath samples in a water-removal device prior to analysis, breath acetone levels determined and corroborated with a mass spectrometer. Finally, a preliminary study probing acetone in the ultraviolet is presented. Utilising an LED centred at 280 nm with a low finesse optical cavity and an imaging spectrograph, detection of 25 ppm of acetone is demonstrated and possible vibronic structure resolved. Combining large absorption cross-sections with the potential to be compact and commercially viable, further development of this arrangement could ultimately represent the optimum solution for breath acetone detection.

This thesis concerns several advances in electroanalytical chemistry which are separated into four parts: the electrochemical investigation of diffusional behaviour, the mechanistic and kinetic study of electrochemistry with room temperature ionic liquids (RTILs), the study of weakly-supported electrochemistry and a comparison of the Butler-Volmer and Marcus-Hush kinetic theories of electron transfer. A study of the diffusional behaviour of electroactive species is essential for further studies, especially in the case when electrochemistry is complicated through ion-pairing interactions between the electroactive species and other electrolytes. In Part II of this thesis, the possibility of the ferricenium ion-paired with perchlorate and hexauorophosphate in acetonitrile was discussed firstly employing chronoamperometric technique. Afterwards, the hexaammineruthenium III/II couple supported by chloride, nitrate and sulfate respectively was studied by a similar method. In order to avoid unwanted ion-pairing effects, room temperature ionic liquids can be applied as solvent, which provide high conductivity by their own ionic nature so that experiments can be conducted without adding additional supporting ions. Because of RTILs have distinctive properties, for example, high viscosity, high conductivity and ionic nature, electrochemistry could be greatly changed compared to those in conventional solvents. Part III of this thesis gives a detailed description of this topic. First, a study of the reduction of 1,4-benzonquinone in 1-ethyl-3-methylimidazolium bis(triuoromethanesulfonyl)imide is presented to show the new mechanistic insight into comproportionation in a electrochemical process. Second, a discussion of the oxidation of hydroquinone in the same RTIL is introduced to suggest a possible ECE scheme which was never reported before. The interest of weakly supported electrochemistry is also well-established, which not only provides another alternative strategy to avert ion-pairings but also offers more physical insights into electrochemical processes. Quantitative methods analysing voltammetries without an excess amount of supporting electrolyte are developed by introducing a migration term into the mass transport equation. In Part IV, new mechanistic insights into the reduction of 2-nitrobromobenzene and the dimerisation of 2,6-diphenylpyrylium in acetonitrile were provide by using weakly-supported cyclic voltammetry. Also, pulse techniques was also adopted to investigate the reduction of cobaltocenium and cobalt(III) sepulchrate, giving an alternative way for electrochemical analysis. A major application of electroanalytical chemistry is investigating electrochemical kinetics. Two kinetic models mostly concerned by electrochemists are Butler-Volmer and Marcus-Hush formalisms. The classic phenomenological model, Butler-Volmer formalism successfully describes most common electron transfer kinetics but shows little reference with nature of the involved species, solution and electrode material, while a more physically insightful theory, the Marcus-Hush formalism, takes species natural properties, for instance, a change of distances or geometry in the solvation or coordination shells of the redox, into account although it requires more complex formulations. Comparative studies of these two theories are presented in Part V in order to improve our understanding of the electron transfer kinetics under different circumstances. First, comparison of cyclic voltammograms of the reduction of europium(III) and 2-methyl-2-nitropropane at mercury microhemispherical electrodes was carried out. Second, square wave and differential pulse voltammetric techniques were also employed to further discriminate the two kinetic models. These studies all find that the symetric Marcus-Hush theory assuming the reactants and products have identical force constant dose not satisfactorily agree with the experimental results. Hence, the introduction of asymmetric Marcus-Hush theory was presented considering different oxidative and reductive reorganization energies, which gives reasonable agreement with experiments and makes this theory more insightful.

Graphene, as a recently discovered carbon allotrope, possesses with it many outstanding properties ranging from high electrical conductivity to great mechanical strength. Single layer graphene can be prepared by mechanical cleavage of graphite or by a more sophisticated method, CVD. However, the scale-up process for these preparation techniques is still unconvincing. Solution-processed graphene from exfoliation of graphite oxide on the other hand provides an alternative prospect resulting in the formation of graphene nanoplatelets (GNPs), which can be readily manipulated to tailor-suit various application demands. The main aim of the thesis is to explore the possibility and availability of this versatile method to produce graphene nanoplatelet and its composites with good all-round performance in energy and bioanalytical applications. A range of physical and chemical characterisation techniques were utilised including SEM, TEM, AFM, XPS, XRD, DLS, FTIR, Raman and UV-Vis spectroscopy in order to investigate the structural and chemical information of the graphene-based materials prepared. Functionalisation of graphene oxide with polyelectrolyte polymer could facilitate deposition of platinum nanoparticles in the formation of Pt-GNPs composites. The resultant composite was employed for bioanalytical application in the detection of an important neurotransmitter, glutamate, based on glutamate oxidase enzyme. The performance of Pt-GNPs based glutamate sensor exhibited enhanced sensitivity and prolonged stability compared to the sensors based on Pt decorated diamond or glassy carbon electrodes. The significant interfering effect from concomitant electrochemically active biological compounds associated with Pt-GNPs electrode however could be alleviated via opting for Prussian blue deposited GNPs electrode instead. The oppositely charged Pt-GNPs due to different functionalising polymers were also subject to self-assembly, which was enabled by the electrostatic interaction of the opposite charges of Pt-GNPs. The self-assembled film showed enhanced mechanical stability than the conventional drop-casted film and provided reasonably good activity towards oxidation of hydrogen peroxide. Three-component composite of graphene, nanodiamond and polyaniline was prepared via in-situ polymerisation for usage as an electrode material in electrochemical capacitors ("supercapacitors"). The addition of graphene was shown to significantly enhance specific capacitance while nanodiamond could improve the stability of the electrode by strengthening the polymer core. Another approach to produce a supercapacitor was via electrodeposition of nickel and cobalt hydroxides on graphene oxide film corporated with bicarbonate salt. The film was then subject to thermal reduction of GO and expansion of graphene layers within the film was observed. This leavening process enhanced the surface area of graphene film and thus the higher specific capacitance was obtained. The decoration of nickel and cobalt hydroxides onto the film also boosted the specific capacitance further however the poor cycling stability of the heated film still remained an issue. Graphene nanoplatelets were also used as a support for electrodeposition of Pt nanoparticles for methanol oxidation in acidic media. The preferential phase of the Pt deposited and large surface area of graphene in comparison to other carbon supports studied led to good catalytic activity being observed.

A new and flexible velocity-map ion imaging apparatus, designed for the study of photodissociation processes and photon-initiated bimolecular reactions in a single molecular beam, has been constructed, developed and characterised. An image Legendre moment fitting analysis was developed to allow recovery of centre-of-mass (CM) angular scattering and kinetic energy release distributions from velocity-map ion images of the products of photon-initiated bimolecular reactions. The Legendre moment analysis methodology has been applied to images of the HCl(v' = 0,j' = 0-6) products of the reactions of Cl(²P_3/2) atoms with ethane and n-butane at collision energies of 0.24 eV and 0.32 eV respectively. The Cl(²P_3/2) reactants were generated by polarised laser photodissociation of Cl₂ at 355 nm. For reaction with ethane, the CM angular scattering distributions show a steady trend from forward scattering at low j' to more isotropic, but backward peaking, scattering at high j'. An impact parameter-based mechanism is proposed to account for the observed dynamics. Abstraction of a hydrogen atom from a primary carbon site in n-butane is seen to produce rotationally very cold HCl products that are forward scattered, whereas H atom abstraction from a secondary carbon site in n-butane yields more isotropically scattered HCl products formed with higher rotational excitation. A peripheral mechanism is proposed to operate for the primary abstraction channel, whilst a more rebound type mechanism is seen to account for the dynamics of the secondary abstraction channel. Around 22% and 30% of the available energy is found in internal modes of the alkyl radical co-products of the Cl + C₂H₆ and Cl + n-C₄H₁₀ reactions respectively. Possible sources of alkyl co-product excitation are discussed in each case. The hydrogen or deuterium atom abstraction reactions of Cl(²P_3/2) with CH₄, CD₄ and CH₃D, have been studied at mean collision energies around 0.3 eV. Chlorine atom reactants were generated by polarised laser photodissociation of Cl₂ at 308 nm. The methyl radical products were detected using (2+1) resonance-enhanced multi-photon ionisation, coupled with velocity-map ion imaging. The laboratory frame speed distributions obtained from the images are in excellent agreement with previous work. The interpretation of the experiments is shown to be very sensitive to assumptions made about the reactant velocity distributions. If these are assumed to be narrow, the data are seen to suggest that a significant fraction of the product signal must arise from the reaction of Cl with vibrationally excited methane reactants. This conclusion is in agreement with previous photon-initiated reaction studies. However, by allowing for the spread in collision energies in the molecular beam, it is shown that it is possible to fit the data sensibly assuming reaction with vibrational ground state methane alone. CM angular scattering distributions thereby derived are presented for all three reactions.

The microwave spectrum of the open-shell van der Waals complex NO-HF has been recorded in the region 6-20GHz using a pulsed nozzle Fourier transform microwave spectrometer. This is the first observation of the microwave spectrum of a open-shell van der Waals complex between two molecules. The spectrum exhibits a rich hyperfine structure with the observation of intermolecular hyperfine interactions in an isolated system providing a sensitive probe of electron transfer in the complex. The spectrum consists of four fine structure transitions 5/2(e)-3/2(e), 3/2(e)-1/2(e), 5/2(f)-3/2(f), 3/2(f)-1/2(f) which have been fitted to a semi-rigid Hamiltonian developed to include the effects of the orbital and spin angular momenta of the unpaired electron on NO. A new treatment to account for the intermolecular hyperfine interaction was developed. The structure of the complex has been determined and is significantly bent with an angle of between 37 degrees and 49 degrees between the NO internuclear axis and the a-axis of the complex. The Renner-Teller parameter, epsilon 2, is very large and negative having the value of -10 449.32(4)GHz indicating that configuration with the unpaired electron in the plane of the complex is more stable. The analysis of the hyperfine interactions of the hydrogen and fluorine nuclei uses two constants for each nucleus, one for the spatial relationship between the magnetic moments of the unpaired electron and the nuclear magnetic moment and a Fermi-contact term. The Fermi-contact term for hydrogen is the first strong evidence of intermolecular charge transfer in an isolated van der Waals molecule.

This thesis describes the application of a wide variety of data processing methods, in particular the Maximum Entropy Method (MEM), to data from Nuclear Magnetic Resonance (NMR) experiments. Chapter 1 provides a brief introduction to NMR and to data processing, which is developed in chapter 2. NMR is described in terms of the classical model due to Bloch, and the principles of conventional (Fourier transform) data processing developed. This is followed by a description of less conventional techniques. The MEM is derived on several grounds, and related to both Bayesian reasoning and Shannon information theory. Chapter 3 describes several methods of evaluating the quality of NMR spectra obtained by a variety of data processing techniques; the simple criterion of spectral appearance is shown to be completely unsatisfactory. A Monte Carlo method is described which allows several different techniques to be compared, and the relative advantages of Fourier transformation and the MEM are assessed. Chapter 4 describes in vivo NMR, particularly the application of the MEM to data from Phase Modulated Rotating Frame Imaging (PMRFI) experiments. In this case the conventional data processing is highly unsatisfactory, and MEM processing results in much clearer spectra. Chapter 5 describes the application of a range of techniques to the estimation and removal of splittings from NMR spectra. The various techniques are discussed using simple examples, and then applied to data from the amino acid iso-leucine. The thesis ends with five appendices which contain historical and philosophical notes, detailed calculations pertaining to PMRFI spectra, and a listing of the MEM computer program.

Conjugated Polymers have attracted a great deal of research interest in recent years due to their optoelectronic properties which makes them suitable for applications in organic light-emitting devices (OLEDs) and organic photovoltaics. Their properties are strongly dependent on the electron-electron and electron-nuclear interactions as well as the disorder which is present in almost all systems at finite temperatures. In this thesis the optical properties of electronically neutral conjugated polymers will be investigated. The results obtained are general and applicable to a wide range of parameters. In order to compare these to experiment the optical properties of poly( paraphenylene), poly(para-phenylene vinylene), and derivatives have been calculated. In these polymers the primary photoexcitations are Frenkel excitons which can be described by the Frenkel-Holstein Hamiltonian, which explicitly takes into account the exciton-nuclear coupling. Disorder can be introduced into this model both as diagonal and off-diagonal disorder within the Hamiltonian. First the optical transitions in ordered, linear conjugated polymers are investigated. It is found that the length of the polymer has a direct spectroscopic signature in the emission spectrum. When off-diagonal disorder is introduced the excitons localise on portions of the chain and the length of these portions, the conjugation length, then shows a clear emission signature. As such, a disordered polymer can be described theoretically as a chain of shorter segments, which define chromophores in a polymer context. Following from these calculations the role of conformation was investigated and effects were observed that greatly determine the optical properties of non-linear polymers. Most notable the Herzberg-Teller effect, which renders symmetrically forbidden transitions weakly allowed and greatly affects the absorption and emission spectra. The signatures observed in these spectra allow the determination of the (coarse grained) conformation of the polymer, something that has been difficult to measure directly.

X-ray photoelectron spectroscopy (XPS) of ionic liquids (ILs) has become a valuable tool for the investigations of IL interfacial and physicochemical properties. The complex signals that result from elements which occupy a variety of chemical states, for example the C 1s photoemission, are often interpreted through chemical intuition and peak fitting parameters. This Thesis will present a new method to determine exact photoemission binding energies (B.E.s), through the comparison of multiple spectra. The designer aspect of ILs has been exploited in order to produce salts with small structural modifications. By comparing the C 1s and N 1s photoemissions of the structurally related samples, difference spectra have been produced. These spectra show the relative shifting of electron density between the two signals, revealing the initial and final locations of the changing photoemission. Using this technique, the current C 1s peak fitting models of imidazolium and pyridinium ILs have been examined. A variety of 4,4’-bipyridinium salts have also been used as a structural variation of pyridinium ILs to show how molecular symmetry and normalisation may be utilised in order to produce photoemissions equivalent to fragments of molecules. The subsequent C 1s difference spectra have provided carbon peak fitting models for mono- and di-alkylated 4,4’-bipyridinium salts. Without the use of XP difference spectra, these known fitting models would be almost impossible to determine. Finally, multiple complex difference spectra have been used to identify the exact B.E.s of C 1s photoemissions from a series of nitrile functionalised ILs. The complex difference spectra have also been analysed by inverse Gaussian fittings to show how additional information may be extracted from the characteristic shapes. The ‘construction’ of photoemissions is also demonstrated, whereby known B.E. peaks are assembled to accurately reproduce experimentally determined XP spectra.

Radioisotopes of caesium (Cs) and strontium (Sr) have been distributed in the environment due to weapons testing, nuclear power production and accidents at nuclear facilities. Radiocaesium and radiostrontium are of major concern in the medium to long term following accidental releases as they have high energies, long half lives (137Cs≈30 years; 90Sr≈29 years) and their easy assimilation into biological systems due to their similarity to the biologically important elements potassium (K) and calcium (Ca), respectively. Radio-caesium and -strontium are transferred to humans primarily via plant root uptake, and therefore minimising this uptake has been the focus of a number of remediation strategies, such as ploughing and fertiliser application. Species or cultivar substitution, where a species/cultivar that has higher uptake is replaced by a species/cultivar that has lower uptake, has been proposed as an effective and socially acceptable remediation strategy for contaminated agricultural land, but not enough is known about its efficacy for it to be recommended internationally. The aim of this thesis is to evaluate the potential of species or cultivar substitution as a remediation strategy for contaminated agricultural areas. Chapter 2 consists of meta-analysis of the available data (115 experiments) on the inter-cultivar variation in Cs and Sr accumulation by 27 plant species. Chapter 3 includes experiments conducted in the laboratory (UK) and two experiments in the field (Ukraine) investigating inter-cultivar variation in radiocaesium and radiostrontium accumulation in Brassica oleracea, and whether consistently lower-accumulating cultivars could be identified. Chapter 4 details analysis of samples from grass breeding experiments in Aberystwyth and Edinburgh (UK) from four forage grass species; hybrid ryegrass (Lolium perenne L. x Lolium multiflorum Lam.), L. perenne, L.multiflorum and Festuca arundinacea Shreb., and investigates inter-species and inter-cultivar variation in uptake of stable Cs and Sr. Hybrid ryegrass cultivars that were lower-accumulating in Cs and/or Sr were also identified. Chapter 5 compares the stable Cs and Sr uptake in six L. perenne and two F. arundinacea cultivars grown in Aberystwyth and Narodychi (Ukraine). Chapter 6 compares the performance in terms of yield and forage quality (elemental concentrations, digestibility and water soluble carbohydrate content) of six hybrid ryegrass cultivars and ten F. arundinacea cultivars identified as consistently lower-accumulating in Cs and/or Sr against the performance of two commercial hybrid ryegrass cultivars. The mean inter-cultivar variation in Cs and Sr was 1.8-fold and 2.0-fold,respectively when 27 plant species were studied. Thirty-five-fold variation in radiocaesium and 23-fold variation in radiostrontium was found between c.70 Brassica oleracea cultivars. In two field experiments in Ukraine, five cultivars had consistently lower radiocaesium concentration ratios and two cultivars consistently lower radiostrontium concentration ratios. One cultivar had lower radiocaesium and radiostrontium concentration ratios. Festuca arundinacea cultivars had lower Cs and Sr concentration ratios than cultivars of hybrid ryegrass, L. perenne and L. multiflorum. Three out of 17 hybrid ryegrass cultivars had consistently lower Cs concentration ratios, two cultivars consistently lower Sr and one consistently lower Cs and Sr. Despite differences in soil properties and environmental conditions, F. arundinacea cultivars grown in Aberystwyth and Narodychi accumulated less stable and radioactive Cs and Sr than L. perenne cultivars. One L. perenne cultivar also accumulated less Cs and Sr at both sites. F. arundinacea cultivars accumulated less Cs and Sr than commercial hybrid ryegrass cultivars, but alsohad up to 59% lower yield and a reduction of up to 19% in K accumulation, up to 46% in Ca accumulation, up to 7% in dry matter digestibility and up to 17% in water soluble carbohydrate content. Selecting lower accumulating cultivars was found to reduce Cs and Sr accumulation less, but with a smaller yield penalty and a smaller reduction in digestibility and water soluble carbohydrate content. It is concluded that species and cultivar substitution could be an effective remediation strategy in contaminated agricultural land provided implications for yield and quality are considered.