Polyoxometalates: Cascading Functionality to Unique On‐Off Organic Photoelectrochemical Transistor Operation

Abstract

While existing polyoxometalates (POMs) are predominantly utilized in a range of energy devices, their potential in bioelectronics and optoelectronics, particularly in organic photoelectrochemical transistors (OPECTs), remains unexplored. Here, the potential of POMs in this aspect is unveiled by a POM/sulfide‐gated OPECT. The representative PW12/ZnIn2S4 with cascading light‐harvesting and enzyme‐like functionality enables unique on‐off OPECT operation. The incorporation of PW12 facilitates the separation of photogenerated charge carriers across the heterojunction interface, consequently inducing a pronounced gating effect. Linking with a CRISPR/Cas13a system correlating the target miRNA‐21 and biological generation of H2O2, the PW12 will enable the polymerization of dopamine into polydopamine and thus sensitively inhibit the OPECT gating. Experimental results demonstrated that the developed OPECT sensor achieved good analytical performance with a detection limit as low as 3.9 fm. This study demonstrates the potential of POMs in OPECT. Given the large family and multifunction of POMs, its implications in the diverse bioelectronics and optoelectronics are expected.

Molecule Engineering Metal–Organic Framework-Based Organic Photoelectrochemical Transistor Sensor for Ultrasensitive Bilirubin Detection

“…The organic photoelectrochemical transistor (OPECT) is an innovative biosensing device that integrates the features of organic electrochemical transistors (OECTs) and photoelectrochemical (PEC) biosensing. − Noncontact control, minimal background signal, and exceptional signal amplification capabilities endow the OPECT sensor with promising prospects. − The device elaborately incorporates a tunable light-harvesting component to traditional OECT comprising the source (S) and drain (D) electrodes and the organic semiconductor film 3,4-ethylenedioxythiophene poly(styrenesulfonate) (PEDOT:PSS) . OPECT eliminates the necessity of the instrumental V G bias required for OECT operation, replacing it with photovoltage ( V p ) and thereby transcending the constraint of OECT’s inability to operate at zero V G while amplifying the PEC signal.…”