Innovations in Optical and Electrochemical Sensing: Applications in Biotechnology

INNOVATIONS IN OPTICAL AND ELECTROCHEMICAL SENSING: APPLICATIONS IN BIOTECHNOLOGY T. DI GIULIOa aLaboratory of Analytical Chemistry, Department of Biological and Environmental Sciences and Technologies (Di.S.Te.B.A.), University of Salento, Lecce, Italy A chemical sensor is a device that transforms chemical information into an analytically useful signal. The chemical information, mentioned above, may originate from a chemical reaction of the analyte or from a physical property of the system investigated. They can have applications in different areas such as medicine, home safety, environmental pollution and many others. OBJECT OF THE RESEARCH : SENSORS DEVELOPMENT https://doi.org/10.3390/chemosensors9060123 Sensing platform DEVELOPMENT OF ELECTROCHEMICAL AND OPTICAL SENSORS BASED ON MOLECULARLY IMPRINTED POLYMERS (MIPS) Molecularly imprinted polymers (MIPs) as receptors Sensing platform https://www.cell.com/heliyon/fulltext/S2405-8440%2824%2912220-7 WHY? MOLECULARLY IMPRINTED POLYMERS (MIPS) High versatility in synthetic processes; High degree of freedom in polymer composition, important to modulate the interaction with the target analyte Huge field of applications; MIP artificial receptors https://www.cell.com/heliyon/fulltext/S2405-8440%2824%2912220-7 WHY? MOLECULARLY IMPRINTED POLYMERS (MIPS) High versatility in synthetic processes; High degree of freedom in polymer composition, important to modulate the interaction with the target analyte Huge field of applications; MIP artificial receptors SENSORS BASED ON MOLECULARLY IMPRINTED POLYMERS (MIPS): APPLICATION IN BIOTECHNOLOGY https://spj.science.org/doi/10.1186/s40824-023-00388-5 Environmental monitoring and food analysis Viruses and pathogens Viruses and pathogens SENSORS BASED ON MOLECULARLY IMPRINTED POLYMERS (MIPS): APPLICATION IN BIOTECHNOLOGY https://jast-journal.springeropen.com/articles/10.1186/s40543-022-00344-3 ELECTROCHEMICAL SENSORS SENSORS BASED ON MOLECULARLY IMPRINTED POLYMERS (MIPS): APPLICATION IN BIOTECHNOLOGY https://jast-journal.springeropen.com/articles/10.1186/s40543-022-00344-3 OPTICAL SENSORS Deficiencies in tyrosine hydroxylase lead to a pathophysiology mainly characterized by dystonia and encephalopathy, while tyrosine metabolism deficits, concern the impossibility of catabolizing the amino acid Carnosine Small dipeptide with important functions in the human body (strong antioxidant and anti-glycation properties). Useful to investigate metabolic disorders (e.g., diabetes, kidney disease), where altered carnosine can serve as an early biomarker. Lysozyme ELECTROCHEMICAL SENSORS PROOFS OF MIPS VERSATILITY Tyrosine Changes in Lyz levels can be a symptom of a pathological condition. For example, there is an increase in lysozyme concentrations in case of oral infections, oral squamous cell carcinoma, coronary artery disease docking score: − 7.32 eV Molecular Dynamics (MD) simulations POLYMER INTERACTION WITH THE TARGET: MOLECULAR DYNAMICS SIMULATIONS AN OPTICAL TRANSDUCER FOR OPTICAL SENSORS DEVELOPMENT: NANOPOROUS SILICON (PSIO2) Advantages ▪Large surface area; ▪Highly sensitive response for surface changes. ▪ Label-free sensing. ▪ Cost-effective. ▪ Stability EOT (effective optical thickness): 2nL n: refractive index L: thickness Nanoporous silicon (PSiO2) is generated by electrochemical etching of bulk silicon substrates. MIP synthesis 0 5 10 15 20 25 30 35 40 400 450 500 550 600 650 700 750 800 Reflectance (%) Wavelength (nm) bare nPSiO2 APTES functionalization CDI/Quercetin anchoring 0 5 10 15 20 25 30 35 40 400 450 500 550 600 650 700 750 800 Reflectance (%) Wavelength (nm) CDI/Quercetin anchoring PPy synhtesis Template removal PPY-BASED MIP FOR QUERCETIN (QU) 0 50 100 150 200 250 300 350 400 450 500 APTES functionalization Target anchoring PPy synthesis Template removal EOT-EOTPSiO2 (nm) PSiO2functionalization steps 0 5 10 15 20 2.5 5 10 20 EOT-EOT0(nm) [Quercetin] (M) 2h 1h 30min SENSOR FOR WINE ANALYSIS monomer (metallo-porphyrin) template (carnosine) metal-ion mediated interaction CV: 0 to 1.1 V to Au disk electrode vs SCE SCAN-RATE: 200 mV s-1 for 15 cycles solution: 0.1 mM metalloporphyrin containing 0.1 mM carnosine in ACN/H2O (9:1, v/v). Resulting cyclic voltammogram Electropolymerization ELECTROCHEMICAL SENSOR BASED ON ELECTRO-SYNTHESIZED MIP FOR CARNOSINE CV EIS ELECTROCHEMICAL CHARACHERIZATION OF MIP SYNTHESIS STEPS: CYCLIC VOLTAMMETRY (CV) AND ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) FTIR and XPS characterization of the MIP film Wavenumb er (cm -1) Assignment 1655 Amide I 1648 Amide I 1580 ν C=C imidazole + ring vibration 1565 ν C=C imidazole + ring vibration 1510 δ N-H imidazole 1590 δ N-H imidazole 1406 δ N-H imidazole + ring stretching 1387 δ N-H imidazole + ring stretching polyZnTAPP+carnosine polyZnTAPP C=N -NH, -NH2 pyrrolic NH - N+ FTIR XPS MIP-based sensors performances (1) NIC= Rct−R0/R0 MIP NIP (as control) Randles cell as equivalent circuit After the MIP synthesis, the sensor was immersed in carnosine solutions at increasing concentrations, prepared in phosphate buffer at pH 7.4. The incubation time is 30 min. CARNOSINE DETECTION TESTS MIP Imprinting factor (IF) 8.1 Detection limit 0.055 mM RSD% 3.6% MIP-based sensors performances (2) MIP NIP CARNOSINE DETECTION TESTS