Structure–property correlations in glycine-NaCl composites for possible bio-sensing application

We observe a significant influence of ionic incorporation on the structural, optical, thermal, and electrical properties of amino acid–based functional materials in Glycine: NaCl composites. UV–Vis spectroscopy revealed a blue shift in the absorption edge and modification of the optical transparency, indicating molecular–ionic interactions and defect-level formation. Thermal analysis (TGA–DTA) showed improved stability and altered phase-transition behavior, confirming that NaCl disrupts the hydrogen-bonding environment of glycine. Dielectric measurements exhibited enhanced permittivity (108), strong dispersion, and increased dielectric loss, attributed to dipolar, ionic, and Maxwell–Wagner interfacial polarization. The Cole-Cole plots confirmed non-Debye relaxation and distinct grain and grain-boundary contributions. Nonlinear I-V characteristics and temperature-dependent resistance measurements further evidenced mixed ionic–electronic conduction with hopping based transport mechanism, while heating–cooling resistance hysteresis revealed reversible microstructural and orientational changes. The results highlight Glycine: NaCl composites as promising candidates for low-power electronic components, thermal–electrical switching elements, and bio-compatible sensing applications. NaCl ions enhance charge transport in glycine composites. Composite exhibits dipolar dynamics and interfacial polarization. Ion assisted pathways reduce activation energy. Structure and temperature controls electrical and thermal performance. Promising for low power electronic devices.