Ferrocenylsubstituierte Thiophene: Synthese, Charakterisierung und Polymerisation Technische Universität Chemnitz, Fakultät für Naturwissenschaften Dissertation 2011, 140 Seiten Die Vorliegende Arbeit beschäftigt sich mit der Synthese und dem Reaktionsverhalten von metallocenylhaltigen Thiophenen. Dabei wurden die erhaltenen Metallocenylthiophene mittels Eisen(III)salzen oxidativ polymerisiert und copolymerisiert. Für eine gezielte Synthese von polymeren Verbindungen wurden oligomere Modellverbindungen dargestellt und die erhaltenen Ergebnisse auf eine vielfältig Funktionalisierung in 2- und/oder 5-Position der Thiophenmonomere angewendet. Die somit erhaltenen neuen Monomere lassen verschiedene Polymerisationen und Copolymerisationen, z. B. über eine Negishi-Kreuzkupplungsreaktion zu. Die somit erhaltenen Polymere und Copolymere liegen in der neutralen Form vor und weisen eine regioselektive Kopf-Schwanz-Verknüpfung auf. Es ist damit ein verarbeitbares Polymer zugänglich, welches sowohl im oxidierten Zustand als auch im neutralen Zustand als Polymer-CNT-Hybridmaterial Leitfähig ist.:Inhaltsverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Abkürzungen 1.Einleitung 2.Kenntnisstand 2.1 Leitfähige Polymere 2.1.1 Leitfähigkeit in Kunststoffen 2.1.2 Polymere auf Basis von Heterocyclen 2.1.3 Poly(3-alkylthiophene) 2.1.4 Poly(3,4-ethylendioxythiopen) 2.1.5 Übergangsmetall-Polythiophen-Hybridmaterialien 2.1.5.1 Metallhaltige Polythiophene des Typ I 2.1.5.2 Metallhaltige Polythiophene Typ II 2.1.5.3 Metallhaltige Polythiophene des Typs III 3.Ergebnisse und Diskussion 3.1 Metallocenyfunktionalisierte Thiophene 3.1.1 Synthese und Charakterisierung 3-metallocenylsubstituierter Thiophene 3.1.2 Polymerisation von 3-Metallocenylthiophenen 3.1.3 Synthese und Chrakterisierung von 3-(4-(ferrocenyl)phenyl)thiophen (15) 3.1.4 Optimierung der oxidativen Polymerisation von 3-Ferrocenylthiophen (5) 3.2 Copolymerisationen von 3-Ferrocenylthiophen (5) 3.2.1 Copolymerisation von 5 mit 3-Hexylthiophen (17) 3.2.2 Copolymerisation von 5 mit 3,4-Ethylendioxythiophen (19) 3.2.3 Leitfähigkeitsuntersuchungen von Poly(3-metallocenylthiophenen) 3.3 Synthese und Charakterisierung von in 2- und / oder 5- Position substituierten 3-Ferrocenylthiophenen 3.3.1 Bromierung von 3-Ferrocenylthiophen (5) 3.3.2 Formylierung von 3-Ferrocenylthiophen (5) 3.3.2.1 Synthese von 3-Ferrocenylthiophen-2-carbaldehyd (29) 3.3.2.2 Synthese von 3-Ferrocenylthiophen-5-carbaldehyd (30) 3.3.2.3 Synthese von 2-Dimethoxymethyl-3-ferrocenylthiophen (31) 3.3.2.4 Synthese von 3-Ferrocenylthiophen-2,5-dicarbaldehyd (34) 3.3.2.5 Synthese von 5-Methyl-3-ferrocenylthiophen (35) 3.3.2.6 Synthese von 5-Methyl-3-ferrocenylthiophen-2-carbaldehyd (40) 3.3.2.7 Charakterisierung der aldehydfunktionalisierten 3-Ferrocenylthiophene 3.3.3 Hydroxymethylierung von 3-Ferrocenylthiophen (5) 3.3.3.1 Synthese von hydroxymethylierten 3-Ferrocenylthiophenen 42-44 3.3.4 Synthese von metallocenylhaltigen oligomeren Modellsystemen 3.3.4.1 Synthese von Trimeren unter Verwendung verschiedener Dibromthiophene 3.3.4.2 Synthese von 1,4-bis(2-(3-ferrocenylthiophen-2-yl)vinyl)benzen (55) 3.3.5 Charakterisierung der oligomeren Modellsysteme 50, 51 und 55 3.4 Einführung löslichkeitsvermittelnder Gruppen in 3-Ferrocenylthiophen (5) 3.4.1 Synthese von 3-(1’-Butylferrocenyl)thiophen (60) 3.4.2 Synthese von 2-Brom-4-(1’-butylferrocenyl)thiophen (62) 3.4.3 Charakterisierung der Butylferrocenylthiophene 60 und 62 3.5 Polymerisation und Copolymerisation der synthetisierten Monomere 3.5.1 Polymerisation von 2-Brom-4-ferrocenylthiophen (22) zu 64 3.5.2 Polymerisation von 3-Ferrocenyl-5-methylthiophen-2-carbaldehyd (40) zu 67. 3.5.3 Polymerisation von 3-Ferrocenylthiophen-2,5-dicarbaldehyd (34) zu 70 3.5.4 Polymerisation von 3-Ferrocenyl-5-hydroxymethylthiophen (43) zu 75 3.5.5 Polymerisation von 2-Brom-4-(1’-butylferrocenyl)thiophen (62) zu 77 3.5.6 Copolymerisation von 3-Ferrocenylthiophen-2,5-dicarbaldehyd (34) mit 52 zu 78 3.5.7 Copolymerisation von 3-Ferrocenylthiophen (5) und 2,5-Dibrom-3,4-ethylendioxythiophen (48) zu 81 3.5.8 Copolymerisation von 3-(1’-Butylferrocenyl)thiophen (60) und 2,5-Dibrom-3,4- ethylendioxythiophen (48) zu 85 3.5.9 Dotierung und Leitfähigkeitsuntersuchungen der synthetisierten Polymere 10, 64, 67, 75, 77, 78, 81 und 85 3.6 Cyclovoltammetrische Untersuchungen 3.6.1 Cyclovoltammetrische Untersuchungen ausgewählter Verbindungen 3.7 UV-Vis-spektroskopische Eigenschaften ausgewählter Verbindungen 3.8 Einbettung von Carbonanotubes (CNTs) in Polythiophen-Filme 3.8.1 Herstellung der Polymer-CNT-Hybridmaterialien und verwendete Geräte 3.8.2 Charakterisierung der Polymer-CNT-Hybridmaterialien 3.8.2.1 Optische Charakterisierung 3.8.2.2 Leitfähigkeitsmessungen 4.Experimenteller Teil 4.1 Arbeitstechniken und verwendete Geräte 4.1.1 Arbeitstechniken 4.1.2 NMR-Spektroskopie 4.1.3 Elementaranalyse 4.1.4 Schmelzpunktbestimmung 4.1.5 IR-Spektroskopie 4.1.6 UV-Vis-Spektroskopie 4.1.7 ESI-TOF-Massenspektrometrie 4.1.8 Cyclovoltammetrie 4.1.9 Einkristallröntgenstrukturanalyse 4.2 Verwendete Ausgangsverbindungen 4.3 Synthesevorschriften 4.3.1 Synthese von 3-Ferrocenylthiophen (5) 4.3.2 Synthese von 3-Ruthenocenylthiophen (9) 4.3.3 Synthese von Poly(3-ferrocenylthiophen) (10) 4.3.4 Synthese von Poly(3-ruthenocenylthiophen) (11) 4.3.5 Synthese von (1-Ferrocenyl-4-thienylbenzen) (15) 4.3.6 Synthese von Oligo(1-Ferrocenyl-4-thienylbenzen) (16) 4.3.7 Synthese des Copolymers aus EDOT und 3-Ferrocenylthiophen (20) 4.3.8 Synthese von 2-Brom-4-ferrocenylthiopen (22) 4.3.9 Synthese von 3-Ferrocenylthiophen-2-carbaldehyd (29) 4.3.10 Synthese von 3-Ferrocenylthiophen-5-carbaldehyd (30) 4.3.11 Synthese der Dimethoxymethyl-3-ferrocenylthiophene 31 und 32 4.3.12 Synthese von 3-Ferrocenylthiophen-2,5-dicarbaldehyd (34) 4.3.13 Synthese von 3-Ferrocenyl-5-methylthiophen (35) 4.3.14 Synthese von 3-Ferrocenyl-5-methylthiophen-2-carbaldehyd) (40) 4.3.15 Allgemeine Synthesevorschrift für Hydroxymethyl-funktionalisierte 3-ferrocenylthiophene (42, 43 und 44) 4.3.16 Allgemeine Synthesevorschrift für die Herstellung der Terthiophene 49, 50 und 51 4.3.17 Synthese von 1,4-Bis((E)-2-(3-ferrocenylthiophen-2-yl)vinyl)-benzen) (55) 4.3.18 Synthese von 3-(1’-Butylferrocenyl)thiophen (60) 4.3.19 Synthese von 2-Brom-4-(1’-Butylferrocenyl)thiophen (62) 4.3.20 Polymerisationen von 2-Brom-4-ferrocenylthiophen (64) 4.3.21 Polymerisationen von 3-Ferrocenyl-5-methylthiophen-2-carbaldehyd (67) 4.3.22 Polymerisationen von 3-ferrocenyl-2,5-dicarbaldehyd (70) 4.3.23 Polymerisationen von 5-Hydroxymethyl-3-ferrocenylthiophen (75) 4.3.24 Polymerisationen von 2-Brom-4-(1’-Butylferrocenyl)thiophen (77) 4.3.25 Copolymerisationen von 3-ferrocenyl-2,5-dicarbaldehyd (34) mit 52 zu 78 4.3.26 Copolymerisationen von 3-(Ferrocenyl)thiophen mit EDOT (81) 4.3.27 Copolymerisationen von 3-(1’-Butylferrocenyl)thiophen mit EDOT zu 85 4.4 Meßdaten zu den Röntgenstrukturanalysen 5.Zusammenfassung und Ausblick 6 Dank Literaturverzeichnis Selbstständigkeitserklärung Lebenslauf Liste der Publikationen, Poster und Vorträge

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[pt] Este trabalho investiga o impacto de suspensões de grafeno funcionalizado sobre reologia de uma dispersão aquosa de Carbopol. Os derivados de grafeno usados foram óxido de grafeno (GO) e óxido de grafeno amino funcionalizado (AFGO). A variação da concentração e do grau de oxidação do grafeno funcionalizado foram avaliadas e relacionadas à reologia das suspensões. O GO foi produzido a partir da síntese de óxido de grafite pelo método de Hummers modificado, e caracterizado pelas técnicas de DRX, Raman, TGA, FTIR, XPS, TEM e AFM. O GO foi funcionalizado com trietilenotetramina por reação assistida por microondas para produzir AFGO, caracterizado por TGA e XPS. As suspensões foram caracterizadas por experimentos de potencial zeta e testes reológicos de escoamento em estado estacionário e oscilatório. A caracterização do GO mostra que grupos funcionais oxigenados foram incorporados em sua superfície grafítica. O GO oxidado por 96 horas (GO 96 h) apresentou maior distância interplanar e também apresentou menos camadas quando comparado com GO oxidado por 2 horas (GO 2 h). A caracterização do AFGO aponta que grupos aminados foram covalentemente ligados às nanofolhas GO e o GO com maior grau de oxidação produziu AFGO com maior nível de aminação. Todas as nanofolhas sintetizadas são coloidalmente estáveis quando suspensas em meio neutro. Todas as suspensões foram bem modeladas pela equação de Hershel-Bulkley. O aumento da concentração de nanofolhas nas suspensões prejudica a microestrutura do fluido e leva a uma diminuição da viscosidade, tensão de escoamento e elasticidade. O GO 96 h promoveu menor decréscimo na viscosidade, tensão de escoamento e elasticidade do que a suspensão GO 2 h. No caso do AFGO, o maior grau de aminação pode levar a uma queda mais pronunciada nas propriedades reológicas da suspensão. Para a suspensão com maior concentração de GO 96 h, observou-se o aparecimento de histerese em baixas taxas de cisalhamento. Esses resultados mostram que pequenas mudanças na superfície das nanofolhas de grafeno funcionalizado podem influenciar as respostas reológicas de um fluido não newtoniano. / [en] This work investigates the impact of functionalized graphene suspensions on the rheology of a Carbopol aqueous dispersion. The graphene derivatives used were graphene oxide (GO) and amino-functionalized graphene oxide (AFGO). The variation of the functionalized graphene concentration and oxidation was evaluated and related with the suspensions rheology. GO nanosheets were produced from synthesis of graphite oxide by modified Hummers method, and they were characterized by XRD, Raman,TGA, FTIR, XPS, TEM and AFM techniques. The GO was functionalized with triethylenetetramine by microwave assisted reaction to produce the AFGO, which was characterized by TGA and XPS techiniques. The suspensions were characterized by zeta potential experiments and rheological tests through steady-state and oscillatory flow. The GO characterization shows that oxygenated functional groups were incorporated in its graphitical surface. GO oxidized for 96 hours (GO 96 h) showed higher interplanar distance and also presented fewer layers when compared with GO oxidized for 2 hours (GO 2 h). The AFGO characterization points out that aminated groups were covalently attached to the GO nanosheets and the GO with a higher oxidation degree produced an AFGO with higher amination level. All synthesized nanosheets are colloidally stable when suspended at neutral media. All suspensions were well modeled by the Hershel-Bulkley equation. The increase of the nanosheets concentration in the suspensions impairs the level of fluid structure and leads to a decrease in viscosity, yield stress, and elasticity. The GO 96 h promoted a lower decrease in viscosity, yield stress and elasticity than the GO 2 h suspension. In the case of AFGO, the greater amination degree can lead to a more pronounced drop in the suspension rheological properties. For the suspension with a higher concentration of GO 96 h, it was observed the appearance of hysteresis at low shear rates. These results show that small changes in the graphene functionalized nanosheets surface can influence the rheological responses of a non-Newtonian fluid.

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La vaccination est l’un des moyens les plus efficaces de la médecine moderne dans le combat contre les maladies infectieuses. L’amélioration de l’efficacité des vaccins requiert la mise au point d’adjuvants permettant d’accroître la qualité de la réponse immunitaire. À titre d’exemple, les nanoparticules (NP) de poly(acide lactique) (PLA) constituent un système efficace pour la délivrance d’antigènes. Afin de renforcer leur potentiel vaccinal, ce travail de recherche a eu pour objectif d’élaborer des NP de PLA décorées en surface par des molécules immunostimulantes, le D-mannose ou un peptide dérivé de l’interleukine-Beta, et au cœur, par l’imiquimod. Notre stratégie repose sur l’utilisation d’un tensioactif macromoléculaire composé d’un bloc de PLA et d’un bloc de poly(N-acryloxysuccinimide-co-N-vinylpyrrolidone) (P(NAS-co-NVP)), dont les fonctions ester de N-succinimidyle (NS) permettent le couplage de biomolécules. Ce copolymère a été synthétisé par combinaison de la polymérisation par ouverture de cycle et de la polymérisation radicalaire contrôlée par les nitroxydes (NMP). Après l’étude de la copolymérisation du NAS et de la NVP par NMP à partir d’une alcoxyamine modèle (MAMA-SG1), leur copolymérisation a été réalisée à partir de la macro-alcoxyamine PLA-SG1, conduisant au copolymère PLA-b-P(NAS-co-NVP) désiré. Des NP de PLA ont alors été préparées par nanoprécipitation et diafiltration en présence du copolymère, conduisant à des tailles respectives de 150 et 500 nm. Des études de potentiel zêta et de spectrométrie UV ont démontré la présence des esters de NS à la surface des NP (2.4 fonctions.nm-2), disponibles pour le couplage des biomolécules. Des micelles de copolymère ont été également préparées, après substitution des esters de NS par des sucres, et permettent une encapsulation efficace de l’imiquimod, contrairement aux NP de PLA. Ces systèmes constituent une plateforme flexible d’adjuvants potentiels comme alternative aux adjuvants non biodégradables actuellement utilisés. / Vaccination represents one of the most powerful tools of medicine for the fight against infectious diseases. The improvement of vaccine efficiency needs the development of adjuvants able to increase the quality of the immune response. Poly(lactic acid) (PLA) nanoparticles (NPs) represent an efficient system for antigen delivery. In order to improve their vaccine potential, the goal of this research work was to elaborate PLA NPs decorated at the surface with immunostimulatory molecules, D-mannose or peptide derived from interleukine-Beta, and into the core with imiquimod. Our strategy relies on the use of a macromolecular surfactant composed of a PLA block and a poly(N- acryloxysuccinimide-co-N-vinylpyrrolidone) (P(NAS-co-NVP)) block, whose N-succinimidyl (NS) activated esters allow the coupling of biomolecules. This diblock copolymer was synthesized by the combination of ring opening polymerization and nitroxide mediated polymerization (NMP). After the study of the copolymerization of NAS and NVP by NMP from the MAMA-SG1 model alkoxyamine, their copolymerization was performed from the macro-alkoxyamine PLA-SG1, leading to the desired copolymer PLA-b-P(NAS-co-NVP). PLA NPs were then prepared by nanoprecipitation and diafiltration, in the presence of the copolymer, leading to 150 nm and 500 nm sized particles, respectively. Studies of zeta potential and UV spectrometry demonstrated the presence of NS-activated esters at the NP surface (2.4 functions.nm-2), available for the coupling of biomolecules. Micelles from copolymer were also prepared, after substitution of esters with carbohydrates, and allowed an efficient encapsulation of imiquimod, contrary to PLA NPs. These systems represent a flexible platform of potential adjuvants as an alternative to non-biodegradable adjuvants currently used.

Existing methods for pathogen/pollutant detection or wound infection monitoring employ high-cost instruments that could only be operated by trained personnel, and costly device-based detection requires a time-consuming field-to-lab process. This expensive process with multiple prerequisites prolongs the time that patients must wait for a diagnosis. Therefore, improved methods for point-of-care biosensing are necessary. In this study, we aimed to develop a direct, easy-to-use, portable, low cost, highly sensitive and selective sensor platform with the goal of pollutant detection and wound infection/cancer migration monitoring. This study has two main parts, including microfluidic, electrical, and optical sensing platforms. The first part, including chapters 2, 3, and 4, focuses on Bisphenol A (BPA) lateral flow assay (LFA) detection; the second part, including chapter 5 focuses on the electrical sensing platform fabrication for one of the markers of inflammation, matrix metalloproteinases-9 (MMP-9), monitoring/detection. In chapters 2, 3, and 4, we found that the few lateral flow assays (LFAs) established for detecting the endocrine-disrupting chemical BPA have employed citrate-stabilized gold nanoparticles (GNPs), which have inevitable limitations and instability issues. To address these limitations, in chapter 2, a more stable and more sensitive biosensor is developed by designing strategies for modifying the surfaces of GNPs with polyethylene glycol and then testing their effectiveness and sensitivity toward BPA in an LFA. In chapter 3, we describe the development of a new range-extended bisphenol A (BPA) detection method that uses a surface enhanced Raman scattering lateral flow assay (SERS-LFA) binary system. In chapter 4, we examine advanced bisphenol A (BPA) lateral flow assays (LFAs) that use multiple nanosystems. The assays include three nanosystems, namely, gold nanostars, gold nanocubes, and gold nanorods, which are rarely applied in LFAs, compared with general gold nanoparticles. The developed LFAs show different performances in the detection of BPA. In chapter 5, a stable electrical sensing platform is developed for MMP-9 detection.

Highly fluorescent conjugated polymers (CPs) are an important class of biomaterials used for various biological applications including labelling, sensing, and delivery of biological substances. Synthetic versatility and tunable emission make CPs a superior class of biomaterials. Understanding the structure-function relationship of CPs plays a vital role in designing high performing biomaterials. The cationic CPs are self-assembled to conjugated polymer nanoparticles (CPNs) in an aqueous environment due to their amphiphilicity. The physical and biophysical properties of CPNs are highly dependent on the chemical functionality and backbone structure of CPs. Modulation of the surface property and backbone structure of CPNs play an important role for efficient internalization of CPNs into cells. The goal of this dissertation is to understand the structure function relationship of CPNs in an aqueous environment and the change in their photo physical properties upon the self-assembly of CPNs with different backbone structure upon complexation with biologically significant polysaccharides and cell membrane. This work presents the self-assembly of a set of four cationic CPs with different connectivity and backbone structure upon complexation with a linear polyanion hyaluronic acid (HA). The study of photo physical properties changes upon the complexation with series of Glycosaminoglycans (GAGs) provides more insight about how the self-assembly behavior of cationic CPs changes upon the exposure to negatively charged polysaccharides. The understanding of the self-assembly of CPNs with negatively charged biologically important macromolecules under in vitro conditions can give us an idea of photophysical property changes of CPNs during the treatment of CPNs in the cellular environment. The study of the interaction of CPNs with cell membranes using scanning ion conductance microscopy (SICM)-based topography, potential mapping, and confocal microscopy imaging is presented. CPNs are able to induce transient pore like feature formation on the cell membrane during the cellular internalization process. A comparative study of cellular labelling and delivery of siRNA of five CPNs with guanidine motif is presented. The subcellular localization and delivery of siRNA were dependent on the side chain hydrophilicity. The CPNs fabricated with hydrophilic aminoethoxyethanol possesses excellent cellular imaging with higher siRNA delivery.

Self-assembled monolayers (SAMs) provide well-defined and ordered films of molecules spontaneously chemisorbed on a surface. By designing molecules with desired functionalities, such molecular film can be interesting for a range of applications from molecular electronics to catalysis. Important parameters for SAM applications are the film structure and quality, which are dependent on the structure of molecular constituents, the substrate, and the self-assembly process. In this work, SAMs on Au(111) of a variety of functionalized molecules, with thiol and silane headgroups, have been studied using high-resolution X-ray photoemission spectroscopy (HRXPS), near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, Infrared reflection absorption spectroscopy (IRRAS), contact angle measurements and Kelvin probe measurements. In particular, the effects of varying the size of the backbone, varying the headgroup, inclusion of a porphyrin tailgroup, different ways of deprotection of the headgroups, and mixed molecular layers have been investigated. The first part of thesis work is focused on SAMs of oligo(phenyleneethynylene) (OPE) derivatives. First the effect of the extent of the conjugated system on the structure of SAM was investigated. As the lateral π-system in the OPE backbone increases, molecular surface densities become lower and molecular inclinations larger. Subsequently, a bulky porphyrin tailgroup was added onto the OPE molecule. Porphyrin-functionalized OPE with several headgroups were compared and the thioacetyl anchor group was found to form a high quality SAM. In the second part of the work, the molecular orientation of thiol-derivatized tetraphenylporphyrin layers was studied. The geometry of the molecular layer and the number of linkers that bind to the gold surface depend strongly on preparation schemes, i.e. whether or not the acetyl protection groups on the thiol were removed before adsorption. Finally, mixed SAMs of a ferrocene-terminated alkanethiol and alkanethiols were studied. By diluting the ferrocene-functionalized molecules in unfunctionalized alkanethiols, the orientational order and the packing density improved. The geometrical structure and the fraction of the ferrocene-terminated molecules can be tuned by controlling the parameters in the preparation scheme.

<p>Volatile organic compounds (VOCs) are endogenous byproducts of metabolic pathways that can be altered by a disease or condition, leading to an associated and unique VOC profile or signature. Current methodologies for VOC detection include canines, gas chromatography-mass spectrometry (GC-MS), and electronic nose (eNose). Some of the challenges for canines and GC-MS are cost-effectiveness, extensive training, expensive instrumentation. On the other hand, a significant downfall of the eNose is low selectivity. This thesis proposes to design a breathalyzer using chemiresistive gas sensors that detects VOCs from human breath, and subsequently create an interface to process and deliver the results via Bluetooth Low Energy (BLE). Breath samples were collected from patients with hypoglycemia, COVID-19, and healthy controls for both. Samples were processed, analyzed using GC-MS and probed through statistical analysis. A panel of 6 VOC biomarkers distinguished between hypoglycemia (HYPO) and Normal samples with a training AUC of 0.98 and a testing AUC of 0.93. For COVID-19, a panel of 3 VOC biomarkers distinguished between COVID-19 positive symptomatic (COVID-19) and healthy Control samples with a training area under the curve (AUC) of receiver operating characteristic (ROC) of 1.0 and cross-validation (CV) AUC of 0.99. The model was validated with COVID-19 Recovery samples. The discovery of these biomarkers enables the development of selective gas sensors to detect the VOCs. </p><p><br></p><p>Polyethylenimine-ether functionalized gold nanoparticle (PEI-EGNP) gas sensors were designed and fabricated in the lab and metal oxide (MOX) semiconductor gas sensors were obtained from Nanoz (Chip 1: SnO₂ and Chip 2: WO₃). These sensors were tested at different relative humidity (RH) levels, and VOC concentrations. Contact angle which measures hydrophobicity, was 84° and the thickness of the PEI-EGNP coating was 11 µ m. The PEI-EGNP sensor response at RH 85% had a signal 10x higher than at RH 0%. Optimization of the MOX sensor was performed by changing the heater voltage and concentration of VOCs. At RH 85% and heater voltage of 2500 mV, the performance of the sensors increased. Chip 2 had higher sensitivity towards VOCs especially for one of the VOC biomarkers identified for COVID-19. PCA distinguished VOC biomarkers of HYPO, COVID-19, and healthy human breath using the Nanoz. A sensor interface was created to integrate the PEI-EGNP sensors with the printed circuit board (PCB) and Bluno Nano to perform machine learning. The sensor interface can currently process and make decisions from the data whether the breath is HYPO (-) or Normal (+). This data is then sent via BLE to the Hypo Alert app to display the decision.</p>