Nanostructured potentiometric biosensor arrays for chemical fingerprinting of complex liquid matrices: application to minority wine varieties

Abstract

The development of advanced multisensor platforms capable of rapidly analyzing complex chemical matrices remains a key challenge in analytical sensing. In this work, a high- performance potentiometric bioelectronic tongue (bio-ET) is presented as an innovative multisensor system integrating enzyme-functionalized polymeric membranes and nanostructured electron mediators for enhanced analytical performance. The sensing platform is based on arrays of potentiometric biosensors fabricated using carboxylated polyvinyl chloride membranes that enable covalent immobilization of selective enzymes, including glucose oxidase, tyrosinase, laccase, and lyase. To improve electron transfer and signal stability, membranes were modified with gold nanoparticles, generating highly reproducible and sensitive responses.

Individual biosensors displayed linear behavior toward representative analytes such as glucose, catechol, cysteine, and tartaric acid, with detection limits in the order of 10^–4 mol L^–1 and coefficients of variation below 5 %. When combined into a multisensor array, the bio-ET produced cross-selective potentiometric signals suitable for chemometric processing. Principal component analysis demonstrated effective discrimination among minority wines and musts varieties from Castilla y Leon (Spain), highlighting the ability of the system to detect subtle compositional differences in complex hydroalcoholic matrices. Furthermore, partial least squares regression established robust correlations between sensor outputs and conventional physicochemical parameters, including total acidity, pH, sulfur dioxide, anthocyanins, polyphenols, and glucose, with determination coefficients up to 0.98.

The results confirm that enzyme-functionalized potentiometric biosensor arrays enhanced with nanostructured mediators provide a versatile platform for rapid chemical fingerprinting and multicomponent analysis. This approach represents a promising strategy for the development of next-generation multisensor systems targeting complex liquid matrices, combining specificity, cross-selectivity, and advanced data processing within a single analytical tool.

References

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