Hydrovoltaic Effect Coupling with Capacitor Amplification: A Mode for Sensitive Self-Powered Electrochemical Sensing.

Self-powered electrochemical sensors, which can function without external electricity, are incredibly valuable in the realm of sensing. However, most of the present testing methods are normally confined to high environmental requirements, restricted lighting conditions, and temperature differences. Herein, an innovative self-powered electrochemical sensor was successfully developed based on hydrovoltaic effect coupling with capacitor amplification. Due to the combined merits from the two-dimensional transition metal carbides and nitrides (MXene)-polyaniline (PANI) with high surface potential and good hydrophilicity, and the capacitor amplification strategy, the device could harvest electric energy from water evaporation and displayed a high short circuit current value. Under optimal conditions, the proposed self-powered electrochemical sensor presented excellent sensitivity and high specificity for enrofloxacin (ENR) detection in the concentration range from 1 fM to 1 nM with a detection limit of 0.585 fM. Such a proposed sensor also has the advantages of environmental friendliness and ease of use, which is an ideal choice for accurately and precisely detecting ENR in real samples. The mode of such electrochemical detection outlined in this technical note implements a breakthrough in designing self-powered electrochemical sensors, providing a rational basis for development of a diversified sensing platform.

Novel inner filter effect-based near-infrared electrochemiluminescence sensor mediated by well-matched AgBr-nitrogen-doped Ti3C2 MXene and nonmetallic plasmon WO3•H2O.

The development of innovative and efficient strategy is of paramount importance for near-infrared (NIR) electrochemiluminescence (ECL) sensing, which can substantially promote ECL detection in a wide range of situations. Herein, the inner filter effect (IFE) strategy was designed to construct an ultrasensitive NIR ECL biosensor based on the well-matched AgBr nanocrystals (NCs) decorated nitrogen-doped Ti3C2 MXene nanocomposites (AgBr-N-Ti3C2) and hydrated defective tungsten oxide nanosheets (dWO3•H2O). Specifically, the AgBr-N-Ti3C2 nanocomposites displayed extremely effective NIR ECL emission because N-doping could accelerate electron transfer and boost the red-shift of the ECL spectrum. The nonmetallic plasmon dWO3•H2O was used as an absorber due to its facile tuning of the spectra overlap and higher molar extinction coefficients. Time-resolved emission decay curves proved that the decreased ECL intensity was ascribed to the IFE-based steady quenching mechanism. With the support of tetracycline (TC) aptamer and the complementary DNA chain, the fabricated NIR ECL-IFE biosensor performed a wide linear range of 100 nM âˆ¼ 10 fM with a low detection limit of 2.2 fM (S/N = 3), and it exhibited excellent stability, sensitivity, and reproducibility, so as to be applied to real samples. This strategy opens a new avenue to constructing an efficient NIR ECL-IFE system and shows excellent practical potential in actual sample analysis.

Ultrasensitive self-powered photoelectrochemical sensing for enrofloxacin detection by coupling piezoelectric effect with nonmetallic surface plasmon resonance based on ZnO nanorod arrays/WO3-x.

Exploring efficient strategy for high-efficiency photoelectric conversion is quite important to design sensitive self-powered photoelectrochemical (PEC) sensing platform. This work designed a high performance self-powered PEC sensing platform by the integration of piezoelectric effect with localized surface plasmon resonance (LSPR) effect based on ZnO-WO3-x heterostructures. Due to the fluid eddy induced piezoelectric effect by magnetic stirring, the piezoelectric semiconductor ZnO nanorod arrays (ZnO NRs) can facilitate the transfer of electrons and holes by generating piezoelectric potentials under external forces, thereby contributing to the performance of self-powered PEC platforms. Such working mechanism of the piezoelectric effect was studied by using the COMSOL software. Moreover, the introduction of defect engineered WO3 (WO3-x) can further broaden the light absorption and promote the charge transfer owing to the nonmetallic surface plasmon resonance effect. Remarkably, due to the synergizing piezoelectric and plasmonic effect, the photocurrent and maximum power output of ZnO-WO3-x heterostructures were enhanced by 3.3-fold and 5.5-fold than that of bare ZnO, respectively. After the immobilization of the enrofloxacin (ENR) aptamer, the self-powered sensor demonstrated an excellent linearity (1 × 10-14 M to 1 × 10-9 M) with a low detection limit of 1.8 × 10-15 M (S/N = 3). This work undoubtedly holds great promise to provide the innovative inspiration for the formation of high-performance self-powered sensing platform, which opens up a new horizon of potential in food safety and environmental monitoring.