An UiO-66/P-L-histidine composite film fabricated by electropolymerization and electrodeposition for sensing biomarker 4-nitroquinoline N-oxide

Simultaneous Detection of 4-Nitroquinoline-1-oxide and Nitroimidazole Drug Using a Perovskite-BaZrO3@Nb4N5-Nanocomposite-Modified Disposable Carbon Electrode

Pharmaceutical ingredients in water have become a serious threat to living bodies and lead to assorted ecological predicaments. In this study, we have established an electrochemical probe for the simultaneous detection of synthetic pharmaceutical ingredients, including 4-nitroquinoline-N-Oxide (NQN) and ornidazole (ODZ), in both human and environmental samples. This study establishes the detection of NQN and ODZ using a screen-printed carbon electrode (SPCE) modified by highly conducting Nb4N5 incorporated with BaZrO3 perovskite. The electrochemical characteristics of the modified SPCEs were explored by different techniques including electrochemical impedance spectroscopy, differential pulse voltammetry, and cyclic voltammetry. The structural and morphological parameters of the synthesized BaZrO3@Nb4N5 probe were confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller techniques. The modified probe shows excellent sensing characteristics, such as a very low detection limit up to 16.9 nM for NQN and 8.6 nM for ODZ with a wide linear range varying from 0.02 to 84.5 μM and 0.02 to 99.12 μM, respectively. The analytical performance of the modified SPCEs was successfully verified by incorporating the probe for detecting NQN and ODZ in real samples together with wastewater and human urine. Finally, the applicability of our proposed method was validated through a standard HPLC technique.

A selective dual-signal electrochemical paper-based device using imprinted sensors for voltammetric and impedance analysis of 4-NQO and carcinoembryonic antigen (CEA)

BACKGROUND

Carcinoembryonic Antigen (CEA) and 4-nitroquinoline-N-oxide (4-NQO) are cancer markers that play a crucial role in tumor risk assessment and early cancer diagnosis. Therefore, it is in demand to develop a fast, accurate, simple, and cost-effective method to detect these cancer markers for quick and early stage-cancer diagnosis and treatment.

RESULTS

Herein, we report a dual signaling approach for direct and indirect signal transduction of cancer biomarker binding on molecularly imprinted-electrodes integrated on an ePAD, enabling sensitive and selective quantitative analysis of 4-NQO and CEA. Multiple test zones on a single device based on artificial recognition sites using core-shell Cu-MOF@MIP were developed to create a selective "Dual-signal-ePAD". An effective and facile imprinting method on a Cu-MOF surface based on the synthesized of 4-VPBA/MAA/TRIM polymer. It resulted in a novel MIP useable as a high-performance sensing tool for the ultrasensitive and specific quantification of the target cancer biomarkers. Multiple tests consisted of voltammetric analysis of 4-NQO via oxidation of the analyte on a WE1, and impedance analysis of CEA via the molecular interaction with the imprinted WE2.

SIGNIFICANCE

The proposed device provides enhanced electrochemical signal amplification due to its high conductivity, electrocatalytic activity, and the target-specific recognition sites for accurate determination of 4-NQO and CEA targets. The Dual-signal-ePAD exhibits good voltammetric and EIS response, oxidation currents of 4-NQO at -0.06 V and RCT of CEA, resulting in high selectivity and sensitivity with a linear response range covering the concentration range of clinical interest for both analytes. Dual-signal ePAD is a good candidate for clinical screening and POCT.