Strategy for pattern recognition-driven optical chemosensing based on polythiophene

Polythiophenes (PTs) with flexible backbones possess inherent polymer behaviors, including molecular wire effects and dynamic structural changes in π-conjugated systems. The chemical sensing at the functionalized side chains can manipulate such polymer characteristics, resulting in various optical patterns depending on the analyte structures and their concentrations. The unique optical patterns derived from polymer properties contribute to group categorization over a wide concentration range for pattern recognition. This review aims to provide a concise overview of the potential of PT chemosensor arrays using actual sensing examples in environmental monitoring, medical diagnostics, and food analysis. Furthermore, this review summarizes the methodologies that use polymer gels to realize practical chemosensor array chips for onsite analysis.