The present study is targeted on the optimization of the flotation conditions for the improvement of the industrial flotation practice. Part I is focused on the improvement of the flotation of Mountain Pass mine ore for the beneficiation of rare earth elements. The objective is to improve the rare earth recovery of Mountain Pass ore by developing a novel flotation reagents' scheme, meanwhile reducing the flotation temperature to a cost-efficient level and simplifying the flowsheet. Surface chemistry study by contact angle, zeta potential and microflotation tests indicate that a mixed collector consisting of oleic acid (OA) and sodium octanohydroxamate hydrate (OHA) is beneficial for rare earth flotation. More importantly, salicylhydroxamic acid (SHA) is also a promising collector due to the high selectivity. Lab-scale flotation tests using SHA as collector show that 80-90% REE recovery and <20% gangue recovery are achieved at 40°C~60°C, which yield a rougher concentrate of 30%~40% REO. A novel flotation scheme has been developed towards Mountain Pass rare earth mine. The new scheme is of both high selectivity and high recovery, meanwhile the dosage of reagent required is much less, and the flotation temperature is also significantly reduced. Interactive adsorption models are built up through FT-IR and AFM study. The interaction of collector with bastnaesite surface is illustrated. Hydroxamic acid collectors (OHA and SHA) adsorb on bastnaesite surface by forming stable chelating complex. The selectivity of collectors towards bastnaesite flotation is summarized as SHA>OHA>OA. Part II is focused on the improvement of the flotation of Resolution Copper's Superior mine ore at an elevated temperature for the beneficiation of chalcopyrite. Because the Resolution Copper ore is mined from a deep, hot, underground mine, the temperature of ROM (run of mine ore) is much higher than that of the ore usually processed in a typical open-pit copper mine. The ore temperature will still be high during flotation. It is therefore critical to carry out a systemic study on the flotation of Resolution Copper ore at elevated temperatures and clarify the impact on flotation. An overall beneficial effect is observed in high temperature flotation through a lab-scale flotation study. Further action of temperature control is not necessary. The contact angle results indicate that surface hydrophobicity is enhanced at elevated temperature, of which the surface morphology change (shown by AFM images) of xanthate adsorption species (dixanthogen) is the key factor.

Ph.D. (Physics) / Please refer to full text to view abstract

The doping of BiFeO3 with lanthanide elements like Ho, with a radius smaller than Bi, is ideal to improve the ferroelectric and magnetic properties of BiFeO3, which in principle can cause structural distortions of the lattice that improve the electrical and magnetic properties. In this work, we report on the temperature dependence of the structural and magnetic properties of Ho substituted BiFeO3 (BHFO) samples, which have been investigated by X-ray diffraction (XRD) and Mössbauer spectroscopic techniques. The XRD and Mössbauer measurements were done at room temperature on the as-synthesized BHFO samples and after annealing the samples in Argon up to 1073 K. The resultant XRD patterns have shown that BHFO is of rhombohedral R3m space group, with a majority Bi25FeO90 phase and a minority Bi2Fe4O9 phase. These two phases are attributed to the local stoichometry fluctuations in BiFeO3 (BFO). A new phase was evident in the XRD spectra after annealing the sample between 673 – 873 K; this has been assigned to the octahedral B-site of Fe3O4. The Mössbauer spectra were characterized by broadened features and the magnetic hyperfine splitting patterns were indicative of magnetic ordering mostly probably screwed or slightly antiferromagnetic ordering. The spectra were fitted with two symmetric sextets (S1 & S2) which were present in all annealed samples, a symmetric sextet (S3) which was observable at annealing temperatures greater than 673 K, a Lorentzian doublet (D) and a single line (SL) which were present in all spectra. The extracted hyperfine parameters of sextet S1 are consistent with those of rhombohedral BiFeO3 and are characteristic of magnetically ordered Fe3+. At TA > 673 K, a third sextet S3 was assigned to the high symmetry cubic spinel phase. The paramagnetic doublet D was attributed to the Bi25FeO40 phase and the singlet line SL to the Bi2Fe4O9 phase which has been observed previously in the studies of BiFeO3 and other BiFeO3 doped systems. The isomer shift and quadrupole splitting values of the paramagnetic doublet D corresponds to an oxidation state of Fe3+, while the isomer shift of S1 remained fairly constant up to TA = 623 K then decreased gradually after the appearance of S3 indicating an increase of the s-electron density at the Fe nucleus. The quadrupole splitting of S2 showed no systematic change with annealing temperature, however at TA > 623 K this parameter changed dramatically to a negative value with a slightly larger magnetic field. The distribution of the isomer shift and the difference in the quadrupole splitting values and signs are due the variation in the angles between the principal axis of the electric field gradient (EFG) and the spin direction. The hyperfine fields of S1 and S2 remained fairly constant for all measured samples, however at TA > 623 K the hyperfine field of S3 showed a slight increase which could be due to Ho being substituted at the Fe site in BiFeO3. In addition, in-situ Mössbauer measurements at temperatures in the range 300 – 748 K were made on the BHFO samples. The room temperature spectrum showed similar features as observed on the annealing series of measurements. The hyperfine magnetic fields of the two sextet components (S1 and S2) decreased with increasing temperature and finally collapsed at T > 588 K. The hyperfine fields of both the S1 and S2 components decreased systematically with temperature to a field distribution just below the Néel temperature. From our measurements, we estimated the Néel temperature for BHFO to be in the range 598 – 617 K. The isomer shift for all spectral components showed a linear decrease with increasing temperature which closely followed the usual second order Doppler shift variation with temperature. The S1 and S2 spectral components present at room temperature disappeared just before the Néel temperature resulting in the area fraction of the paramagnetic doublet D dominating the spectrum. From the site populations, an average Debye temperature (θD) was estimated to be 240 ± 81 K for BHFO which is lower than the value of 340 ± 50 K cited for BiFeO3.

Thesis advisor: Michael J. Graf / In this work I present a characterization of spin dynamics in LiY1-xHoxF4 over a wide region of frequency - temperature - magnetic field - concentration phase space to probe the onset of magnetic correlations. Specifically, measurements were made of the T = 1.8 K magnetic field and frequency dependence of AC susceptibility, and temperature and field dependence of the longitudinal field positive muon spin relaxation (μSR) for LiY1-xHoxF4 with x = 0.0017, 0.0085, 0.0408, and 0.0855. To determine the concentration range over which the spin dynamics are determined primarily by the Ho3+-μ interaction rather than by the F-μ interaction I characterize the dynamics associated with the formation of the (F-μ-F)−complex by comparing data with Monte Carlo simulations. Numerical simulations of the susceptibility for the x = 0.0017 and 0.0085 are fit to my data and show that Ho-Ho cross-relaxation processes become important at higher concentration, signaling the crossover from single-ion to correlated behavior. The muon spin depolarization is simulated using the parameters extracted from the susceptibility, and the simulations agree well with data for these two samples. It is found that the susceptibility and μSR data for samples with x = 0.0408 and 0.0855 cannot be described within a single-ion picture, possibly due to the onset of collective phenomena. An unusual peak is also discovered in the magnetic field dependence of the muon relaxation rate in the temperature interval 10 – 20 K, and ascribed to a modification of the Ho3+ fluctuation rate due to a field induced shift of the energy splitting between the ground and first excited doublet crystal field states relative to a peak in the phonon density of states centered near 63 cm-1. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

The ligands 2-(bis(2-(octahydro-2-oxobenzo[b][1,4]oxazin-4-yl)ethyl)amino)acetic acid trihydrochloride and bis(2-(octahydro-2-oxobenzo[b][1,4]oxazin-4-yl)ethyl)amine trihydrochloride are synthesized for the formation of Gd(III) complexes, potentially useful as MRI contrast agents. Speciation and hydration numbers of the Gd(III) complexes of 1,7- bis(2-hydroxycyclohexyl)-1,4,7-tris(carboxymethyl)-1,4,7-triazaheptane (Cy2DETA.3A) and 1,7-bis(2-hydroxycyclohexyl)-1,7-bis(carboxymethyl)-1,4,7-triazaheptane (Cy2DETA.2A) can be inferred from spectroscopic studies of the analogous Eu(III) complexes, due to their similar ionic radii, charge and coordination geometry. The phosphorescence emission spectra for the Eu(III) complexes are recorded as function of pH, in buffered and aqueous media. Modulation of the relative intensities of the emission bands is observed for both Eu(III) complexes. Spectroscopically determined pKa values are used to determine potential solution speciation. Ligand pKa values were determined potentiometrically. Attempts were made to correlate results from potentiometric titrations with that of lanthanide luminescent titrations of these complexes. Hydration states (q) were determined for the Eu(III) complexes at spectroscopically significant pH values, in buffered and aqueous media. The results confirm the formation of a octadentate complex between Eu(III) and Cy2DETA.3A, with the inclusion of one H2O molecule in the inner sphere. The complex has high stability and is responsive towards changes in pH and analyte concentration (o-phthalate); potentially suitable as a luminescent sensor. The heptadentate complex formed between Cy2DETA.2A and Eu(III) is substantially weaker, with precipitation of Eu(OH)3 observed at neutral pH, that limits its potential application as a luminescent sensor.

A fibroína da seda (SF) é uma proteína estrutural encontrada nos casulos do Bombyx mori e que possui propriedades potencialmente aplicáveis em fotônica. Esta matriz biocompatível é um substrato interessante para diferentes íons ou moléculas; além disso, o seu índice de refração variável permite que fótons sejam guiados neste material, possibilitando seu uso como guias de ondas biocompatíveis e reabsorvíveis, que pode ser utilizado para fornecer energia ótica para diversas aplicações, por exemplo, terapia ou imagem dentro de tecidos vivos. A sua boa adequação em sistemas ópticos deve-se principalmente a propriedades como: ser mecanicamente robusta, apresentar superfícies muito lisas, altamente transparentes (> 95%) em toda a região visível do espectro e ser modelável. Além disto, há uma característica adicional: a viabilidade de funcionalização bioquímica, o que pode conferir uma maior versatilidade a estes dispositivos. Já os íons terras raras (TR) possuem um papel amplamente conhecido no ramo da fotônica; porém, não há nenhum estudo envolvendo a produção de luz em SF dopada com íons TR, e a combinação das propriedades mecânicas e óticas desta matriz com a multifuncionalidade destes íons pode ser uma forma de se produzir dispositivos fotônicos novos e distintos. Desta forma, o presente trabalho teve como objetivo estudar a estrutura da matriz de SF na presença de diferentes íons TR (Eu3+ e Tb3+), bem como a interação existente entre os aminoácidos que constitui a matriz e estes íons. Os resultados apresentados nesta dissertação mostraram as interações TR-SF e suportam os mecanismos de transferência de energia para excitação de diferentes íons TR nesta matriz, sendo importante para futuras aplicações em fotônica / Silk fibroin (SF) is a structural protein found in Bombyx mori cocoons and has properties that are potentially applicable in photonics. This biocompatible matrix is an interesting substrate for different ions or molecules. Furthermore, its variable refractive index allows for photons to be guided in this material enabling their use as biocompatible and resorbable waveguides, which can be used to provide optical energy for various applications, e. g., therapy or imaging into living tissue. Its suitability in optical systems is mainly due to its properties such as: being mechanically robust, presenting very smooth surfaces, highly transparent (> 95%) throughout the visible region of the spectrum and being moldable. In addition, there is an extra feature: the possibility of biochemical functionalization, which may confer greater versatility to these devices. On the other hand, rare earth ions (RE) play a widely known role in the field of photonics. However, there is no studies involving the production of light in doped SF with RE ions and the combination of the mechanical and optical properties of this matrix with the multifunctionality of these ions can be a way to produce new photonic devices. Thus, the aim of the present work was to study the SF matrix structure in the presence of different RE ions (Eu3+ and Tb3+) as well as the interaction between the amino acids from the matrix and these RE ions. The results presented in this manuscript have characterized the RE-SF interactions and supported the mechanisms of energy transfer for excitation of different RE ions in this matrix being important for future applications in photonics

Os íons terras raras apresentam propriedades espectroscópicas diferenciadas e números de coordenação entre 6 e 12 e seu estado de oxidação mais comum é o íon trivalente. Apesar de esses íons apresentarem uma baixa intensidade de luminescência, em função de sua baixa absortividade molar, esses são capazes de formar complexo onde o ligante absorva luz e transfira para o centro metálico essa energia, fenômeno conhecido como efeito antena. Essas propriedades tornam os seus complexos alvos de estudos como marcadores em ensaios imunoluminescentes, aliado ao uso de nanopartículas poliméricas. Todos esses fatores podem ser utilizados para a montagem de uma metodologia para o diagnóstico da doença de Chagas, doença tropical negligenciada, que apesar de seus mais de 100 anos após descoberta, ainda possui diversas questões em aberto e sem estudo aprofundado. Dessa maneira, propomo-nos a sintetizar e caracterizar nanopartículas de PHB misturadas aos complexos de terras raras, especificamente, complexos -dicetona - Tb3+ , Sm3+ , Gd3+, ou Eu3+. Pretende-se ligar essas nanopartículas a um espaçador como o glutaraldeído ou então diretamente a um anti-IgG humano e assim, num acoplamento antigeno-anticopo verificar sua emissão de luminescência para detecção de soro positivo para a doença. Dessa forma, obtém-se um biomarcador luminescente para diagnóstico da doença de Chagas. / The rare-earth ions exhibit different spectroscopic properties, coordination numbers between 6 and 12 and trivalent is its most common oxidation state. Despite these ions present low luminescence, due to their low molar absorptivity, they are capable of forming complexes where the ligand absorbs light and transfers this energy to the metal center, a phenomenon known as \"antenna effect\". These properties make their complexes object of studies as markers in fluoroimmunoassay allied to the use of polymeric nanoparticles. All these factors can be used for the assembly of a methodology for diagnosis of Chagas\' disease, a tropical overlooked disease, which despite its more than 100 years after discovering, still has several open issues and without thorough study. Thus, We propose to synthesize and characterize PHB nanoparticles labeled with the rare earth complexes, most specifically -diketone complexes - Tb3+ , Sm3+ , Gd3+, or Eu3+ as marker for biological targets. It\'s intended to link these nanoparticles to a glutaraldehyde as a spacer or directly to an anti-human IgG and thus, in a coupling antibody-antigen, verify its luminescence-emission for detecting positive serum sickness. Therefore, we have a luminescent biomarker for diagnosis of Chagas\' disease.

Zeólitas tipo Y contendo terras raras, RE,Ca/NaY (RE = La, Ce, Nd, Eu, Gd), foram preparadas a partir da forma NaY (razão Si/Al = 2,4 ) por trocas iônicas sucessivas com soluções de cloreto de cálcio e cloreto de terras raras, -através de refluxo; e subseqüente filtragem a vácuo, secagem e tratamento térmico sob fluxo de nitrogênio. Após o tratamento térmico, os Íons aquosos trivalentes de terras raras sofrem hidrólise, formando hidroxilas catiônicas do tipo [RE. OH]2+ e prótons H+, tornando-se localizados nas cavidades e canais da zeólita. O próton reage com o oxigênio da rede cristalina, originando centros ácidos muito fortes. O tipo específico de terra rara trocado ionicamente influencia a acidez total, força e distribuição dos sítios ativos na zeólita. As composições químicas das celas unitárias das amostras foram determinadas por espectrometria de emissão atômica por plasma de argônio induzido (ICP-AES). A cristalinidade, após troca iônica e tratamento térmico, foi confirmada por espectroscopia na região do infravermelho (FT-IR) e difração de raios-X. A microssimetria do íon európio na zeólita Eu,Ca/NaY foi investigada por espectroscopia eletrônica de emissão na região do visível, sob excitação de radiação ultravioleta (396 nm). As propriedades ácidas das amostras RE, Ca/NaY foram estudadas por termogravimetria (TG) e calorimetria exploratória diferencial (DSC), usando n-butilamina como molécula sonda. Por TG, foi investigada a acidez total das amostras; enquanto que por DSC, utilizando o modelo cinético de Borchardt & Daniels, foi investigada a força ácida relativa das amostras. A presença dos centros ácidos de Brönsted e Lewis foi determinada por espectroscopia na região do infravermelho (1700-1300 cm-1) , usando piridina como molécula sonda. A atividade catalítica e seletividade das amostras foram avaliadas na reação química modelo de alquilação de benzeno com a olefina linear 1-dodeceno para formação de alquilbenzeno linear. A reação foi estudada na fase líquida, em um microrreator de batelada, à temperatura de 80°C. 0s produtos monoalquilados e os isômeros lineares de 1-dodeceno foram determinados por cromatografia em fase gasosa e espectrometria de massa (GC-MS). / The Y zeolites containing calcium and rare earth polivalent cations, RE,Ca/NaY (RE = La, Ce, Nd, Eu, Gd), were prepared by ion exchange, refluxing the NaY zeolite (Si/Al = 2,4) with calcium chloride and rare earth chloride solutions, followed by thermal treatment under nitrogen flow. The trivalent hydrated rare earth ions undergo hydrolysis, forming [RE.OH]2+ cation hydroxyls and protons H+, which react with oxygen in the lattice, generating strong acid sites. The rare earth elements influence the total acidity, strength and distribution of the active sites in the zeolite. The unit cell chemical compositions of the samples were determined by Inductively Coupled Plasma / Atomic Emission spectroscopy (ICP/AES). The crystallinity was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray diffraction. The europium microsimetry in the Eu,Ca/NaY zeolite was investigated by emission electronic spectroscopy in the visible region, under ultra-violet excitation (396 nm). The acid properties of the RE,Ca/NaY samples were studied by Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC), using n-butilamine as molecular probe. From TG curves, the total acidity was calculated, whereas the relative acid strength was determinated by DSC curves, using the Borchardt-Daniels kinetic model. The nature of Brönsted and Lewis acid sites was investigated by FT-IR, in the 1700 - 1300 cm-1 region, using pyridine as molecular probe. The catalytic activity and selectivity of the samples were evaluated on the alkylation of benzene with 1-dodecene model reaction, to form linear alkylbenzenes, in liquid phase, at 80°C using a bath reactor. The reactant conversion, extent of isomerization and product distribution were monitored by Gas Chromatography and Mass Spectrometry techniques (GC-MS).

Este trabalho concentra-se na preparação e caracterizações estrutural e espectroscópica de materiais nanoestruturados à base de SiO2-Nb2O5 dopados e codopados com íons Er3+, Yb3+ e Eu3+ na forma de pós e guias de onda planares. Os nanocompósitos foram preparados através de uma nova rota sol-gel utilizando óxido de nióbio como precursor em substituição ao alcóxido de nióbio. A correlação estrutura propriedades luminescentes foi estudada por difração de raios X, microscopia eletrônica de transmissão, espectroscopia vibracional de absorção no infravermelho, espectroscopia vibracional de espalhamento Raman, análise térmica, reflectância difusa e especular, espectroscopia de fotoluminescência e acoplamento M-line. Inicialmente foi avaliado a influência da concentração de nióbio nas propriedades estruturais e luminescentes de nanocompósitos (100-x)Si-xNb dopados e codopados com íons Er3+, Yb3+ e Eu3+ tratados termicamente a 900 °C por 3h. A cristalização do Nb2O5 foi dependente da concentração de Nb na matriz, com a distribuição dos íons lantanídeos preferencialmente no Nb2O5, afetando as propriedades luminescentes. Para os nanocompósitos codopados com íons Er3+ e Yb3+ foram obtidos valores de largura de banda a meia altura (FWHM) da ordem de 70 nm na região de 1550 nm e tempos de vida de até 5,2 ms. A emissão na região do visível, decorrente de processos de conversão ascendente, revelou-se dependente da concentração de nióbio. Foi verificada emissão preferencial na região do verde para menores concentrações de Nb. Enquanto que, para as maiores concentrações, processos de relaxação cruzada levaram a um aumento relativo na intensidade de emissão na região do vermelho. A eficiência quântica de emissão dos nanocompósitos (100-x)Si-xNb dopados com Eu3+ variou com o comprimento de onda de excitação, refletindo os diferentes sítios de simetria ocupados por este íons nesta estrutura complexa. A influência da temperatura de tratamento térmico no processo de cristalização do Nb2O5 em nanocompósitos 70Si:30Nb codopados com íons Er3+ e Yb3+ foi avaliada. Material amorfo foi obtido a 700 °C enquanto que a 900 e 1100 °C foram identificas as fases ortorrômbica (fase T) e monoclínica (fase M) do Nb2O5. Intensa emissão na região de 1550 nm com valores de FWHM de 52 e 67 nm e tempos de vida de 5,6 e 5,4 ms foram verificados a 700 e 900 °C sob excitação em 977 nm, respectivamente. Por fim, foram obtidos guias de onda planares com excelentes propriedades ópticas e com grande potencial de aplicação em dispositivos de amplificação óptica. Especificamente, materiais fotônicos com banda larga de emissão na região do infravermelho foram preparados, indicando fortemente a potencialidade para a aplicação em telecomunicações envolvendo não somente a banda C como também as bandas L e S em materiais contendo somente íons Er3+ como centros emissores. / This work focuses on the preparation and structural and spectroscopic characterization of nanostructured materials based on Er3+-, Yb3+-, and Eu3+-doped and co-doped SiO2-Nb2O5 as powders and planar waveguides. A new sol-gel route based on niobium oxide instead of niobium alkoxide was used to prepare the nanocomposites. X ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, TGA/DSC analysis, Diffuse and specular reflectance, photoluminescence spectroscopy, and M-line coupling helped to evaluate the correlation between structure and luminescent properties. Initially, the influence of the Nb content on the structural and luminescent properties of Er3+-, Yb3+-, and Eu3+-doped and co doped (100-x)Si-xNb nanocomposites annealed at 900 °C for 3 h was examined. Nb2O5 crystallization depended on the Nb content; with the lanthanide ions occupied the Nb2O5-rich environment preferentially, which affected the luminescent properties. For the Er3+/Yb3+ co-doped nanocomposites, the full width at half maximum (FWHM) and the lifetime values were as high as 70 nm and 5.2 ms, respectively. The visible emission originating from upconversion processes also depended on the Nb content. For lower Nb concentrations, emission occurred in the green region, whereas cross-relaxation led to emission in the red region for higher Nb concentrations. The emission quantum efficiency of the Eu3+- doped (100-x)Si-xNb nanocomposites changed with the excitation wavelength, showing that these ions occupied different symmetry sites. The effect of the annealing temperature on the Nb2O5 crystallization process was also assessed for the Er3+/Yb3+ co-doped 70Si:30Nb nanocomposites. An amorphous material emerged at 700 °C, whereas the orthorhombic (T-phase) and monoclinic (M-phase) Nb2O5 phases arose at 900 °C and 1100 °C. The nanocomposite emitted in the 1550 nm region under 977-nm excitation. FWHM values of 52 and 67 nm and lifetime values of 5.6 and 5.4 ms were verified at 700 °C and 900 °C, respectively. In conclusion, planar waveguides with excellent optical properties and potential use in optical amplification devices were achieved. More specifically, photonic materials exhibiting an NIR broadband emission were developed. These waveguides are potentially applicable in telecommunication, and materials containing only Er3+ as emitter center should cover not only the C band but also the S and L bands.

Os íons terras raras apresentam propriedades espectroscópicas diferenciadas e números de coordenação entre 6 e 12 e seu estado de oxidação mais comum é o íon trivalente. Apesar de esses íons apresentarem uma baixa intensidade de luminescência, em função de sua baixa absortividade molar, esses são capazes de formar complexo onde o ligante absorva luz e transfira para o centro metálico essa energia, fenômeno conhecido como efeito antena. Essas propriedades tornam os seus complexos alvos de estudos como marcadores em ensaios imunoluminescentes, aliado ao uso de nanopartículas poliméricas. Todos esses fatores podem ser utilizados para a montagem de uma metodologia para o diagnóstico da doença de Chagas, doença tropical negligenciada, que apesar de seus mais de 100 anos após descoberta, ainda possui diversas questões em aberto e sem estudo aprofundado. Dessa maneira, propomo-nos a sintetizar e caracterizar nanopartículas de PHB misturadas aos complexos de terras raras, especificamente, complexos -dicetona - Tb3+ , Sm3+ , Gd3+, ou Eu3+. Pretende-se ligar essas nanopartículas a um espaçador como o glutaraldeído ou então diretamente a um anti-IgG humano e assim, num acoplamento antigeno-anticopo verificar sua emissão de luminescência para detecção de soro positivo para a doença. Dessa forma, obtém-se um biomarcador luminescente para diagnóstico da doença de Chagas. / The rare-earth ions exhibit different spectroscopic properties, coordination numbers between 6 and 12 and trivalent is its most common oxidation state. Despite these ions present low luminescence, due to their low molar absorptivity, they are capable of forming complexes where the ligand absorbs light and transfers this energy to the metal center, a phenomenon known as \"antenna effect\". These properties make their complexes object of studies as markers in fluoroimmunoassay allied to the use of polymeric nanoparticles. All these factors can be used for the assembly of a methodology for diagnosis of Chagas\' disease, a tropical overlooked disease, which despite its more than 100 years after discovering, still has several open issues and without thorough study. Thus, We propose to synthesize and characterize PHB nanoparticles labeled with the rare earth complexes, most specifically -diketone complexes - Tb3+ , Sm3+ , Gd3+, or Eu3+ as marker for biological targets. It\'s intended to link these nanoparticles to a glutaraldehyde as a spacer or directly to an anti-human IgG and thus, in a coupling antibody-antigen, verify its luminescence-emission for detecting positive serum sickness. Therefore, we have a luminescent biomarker for diagnosis of Chagas\' disease.