Contactless Photoelectrochemical Biosensor Based on the Ultraviolet–Assisted Gas Sensing Interface of Three-Dimensional SnS₂ Nanosheets: From Mechanism Reveal to Practical Application

Abstract

This work reports a contactless photoelectrochemical biosensor based on an ultraviolet-assisted gas sensor (UV–AGS) with a homemade three-dimensional (3D)-SnS2 nanosheet-functionalized interdigitated electrode. After rigorous examination, it was found that the gas responsiveness accelerated and the sensitivity increased using the UV irradiation strategy. The effects of the interlayer structure and the Schottky heterojunction on the gas-sensitive response of O2 and NH3 under UV irradiation were further investigated theoretically by 3D electrostatic field simulations and first-principles density functional theory to reveal the mechanism. Finally, a UV–AGS device was developed to quantify the blood ammonia bioassay in a small-volume whole blood sample by alkalizing blood to release gas-phase ammonia with a linear range of 25–5000 μM with a limit of detection (LOD) of 29.5 μM. The device also enables a rapid immunoassay of human cardiac troponin I (cTnI) with a linear range of 0.4–25.6 ng/mL and an LOD of 0.37 ng/mL using a urease-labeled antibody as the immune recognition molecule. Both analyses showed satisfying specificity and stability, suggesting that the device can be applied to practical assays and is of great potential to increase the value of gas-sensitive sensors in chemical biosensing.

Magnetic Rolling Circle Amplification-Assisted Single-Particle Collision Immunosensor for Ultrasensitive Detection of Cardiac Troponin I

“…cTnI is considered a gold marker for the diagnosis of myocardial infarction, whose sensitive and specific detection is very important for the timely diagnosis of the disease. , Due to its simple equipment, fast response, and ultrasensitivity up to single-particle level, a labeled SPCE immunosensor was proposed for the detection of cTnI. Under optimal conditions, collision frequency increased rapidly with cTnI concentrations at first and then slowly, reaching a platform (Figure A).…”

Regenerative Strategy of Gold Electrodes for Long-Term Reuse of Electrochemical Biosensors

“… 2 Different types of materials have been used in the electrodes from the past to the present. Ceramics such as indium tin oxides, 4 , 5 bismuth molybdate (Bi 2 MoO 6 ), 6 and tin sulfide metal oxide (SnS 2 ) 7 are used because of their low cost, electrochemical stability, and physical stability. Conductive polymers such as polyaniline, 8 poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), 9 and polypyrrole (Ppy) 10 are also available, and they have the advantages of conductivity and biocompatibility.…”

Detection of Axitinib Using Multiwalled Carbon Nanotube-Fe2O3/Chitosan Nanocomposite-Based Electrochemical Sensor and Modeling with Density Functional Theory

“…As an alternative to these techniques, electrochemical sensors offer high sensitivity, low cost, environmental- and user-friendliness, ease of use, portability, and short analysis time. , In addition, the fabrication of environmentally friendly sensing systems with low emission and high selectivity at low cost is very important. Taken together, further developments of sensing materials with improved advantageous features by employing innovative nanotechnology strategies, which lead to the design of ultrasmall device mechanisms, is essential. − In fact, the improvement of the sensing properties in modern technologies, as well as re-evaluation of their usability, has been the main challenging task in the current research studies.…”