Multifunctional molecular imprinting-enhanced transistor and electrochemical dual-mode sensor for ultra-wide range...

Accurate quantification of halogenated phenols (HPs) is critical for ecological risk assessment and water safety monitoring due to their high persistence and toxicity, but the wide-range detection of HPs with high specificity in complex matrices remains challenging. Herein, a sensor that integrates extended-gate field-effect transistor (EGFET) and electrochemical (EC) detection modes is developed. The sensing interface is constructed by a multifunctional molecularly imprinted polymer (MIP) with multiple recognition sites and hierarchical conductive network via electrochemical co-polymerization of o-phenylenediamine and 3,4-ethylenedioxythiophene on gold nanodendrites. This innovative design enables complementary signal readouts when analyte binding simultaneously modulates interfacial charge distribution and generates characteristic redox signal. Using 2,4,6-trichlorophenol (TCP) as a model analyte, the sensor achieves a record-wide detection range spanning 7 orders of magnitude where EGFET response covers the lower concentration range (10^-11-10^-6 M) with a detection limit of 1.4 pM, while EC response covers the higher concentration range (10^-7-10^-4 M). The sensor also demonstrates excellent selectivity, regeneration capability, long-term stability, and high accuracy compared with standard high-performance liquid chromatography method in real water sample analysis. This dual-mode sensing strategy offers a new and versatile method for environmental monitoring and on-site water quality assessment.