chemosensors

Chemosensors are devices that convert chemical information from a target analyte into a measurable signal. They are designed to respond selectively to specific chemical species and to produce a signal that can be quantified, such as a change in color, fluorescence, current, or frequency.

A chemosensor comprises a recognition element that binds or reacts with the analyte and a transducer that converts the binding event into an optical, electrical, or mechanical signal. Some designs include a signal processor or readout interface to interpret the signal. The choice of recognition element determines selectivity and sensitivity, while the transducer defines how the signal is generated and measured.

Common transduction methods include electrochemical (changes in current, voltage, or impedance), optical (color change or fluorescence), and mass-sensitive techniques (resonant frequency shifts). Hybrid approaches combine multiple transduction modes to improve reliability.

Recognition elements range from natural receptors such as enzymes, antibodies, and aptamers to synthetic receptors and ionophores that confer selectivity for particular ions, molecules, or classes of compounds.

Key performance metrics include limit of detection, dynamic range, selectivity, response time, reversibility, and stability under operating conditions. Real-world chemosensors are evaluated for accuracy, robustness, and ease of use in complex samples.

Applications span environmental monitoring (pollutants, gases), clinical diagnostics (biomarkers, metabolites), food safety (contaminants, toxins), industrial process control, and security. Ongoing developments aim at miniaturization, integration with electronics, multiplexing, and user-friendly readouts, including smartphone-based platforms.