Biomimetic oxidation of benzo[a]pyrene to a quinone metabolite as a cysteine-oxidation mediator on MWCNT-modified electrode surface

Excited State Kinetics of Benzo[a]pyrene Is Affected by Oxygen and DNA

Benzo[a]pyrene is a widespread environmental pollutant and a strong carcinogen. It is important to understand its bio-toxicity and degradation mechanism. Herein, we studied the excited state dynamics of benzo[a]pyrene by using time-resolved fluorescence and transient absorption spectroscopic techniques. For the first time, it is identified that benzo[a]pyrene in its singlet excited state could react with oxygen, resulting in fluorescence quenching. Additionally, effective intersystem crossing can occur from its singlet state to the triplet state. Furthermore, the interaction between the excited benzo[a]pyrene and ct-DNA can be observed directly and charge transfer between benzo[a]pyrene and ct-DNA may be the reason. These results lay a foundation for further understanding of the carcinogenic mechanism of benzo[a]pyrene and provide insight into the photo-degradation mechanism of this molecule.

An electrochemiluminescence sensor based on CsPbBr3 -zquantum dots and poly (3-thiophene acetic acid) cross-linked nanogold imprinted layer for the determination of benzo(a)pyrene in edible oils

A novel quench molecularly imprinted electrochemiluminescence sensor (MIECLS) based on a covalent organic framework composite (COF-300-Au) with enhanced electrochemiluminescence (ECL) signal from CsPbBr₃ quantum dots and cross-linked 3-thiopheneacetic acid functionalized AuNPs (3-TAA@AuNPs) was developed for the detection of the environmental pollutant benzo(a)pyrene (BaP). A composite material constructed of COF-300-Au with a large specific surface area served as the sensor's support substrate, providing more CsPbBr₃ and imprint recognition sites. Electropolymerization was then employed to form an AuNPs three-dimensional imprinting layer with polythiophene cross-linked using BaP as a template and 3-TAA@AuNPs as a functional monomer. A specific cross-linked imprinting recognition effect was recorded on BaP along with the quenching effect of quinones. The density functional theory (DFT) evaluation of the binding mechanism between 3-TAA@AuNPs and BaP revealed powerful MIECLS toward the detection of BaP at concentrations ranging from 10^-14 to 10^-5M, with a detection limit of as low as 4.1 × 10^-15 M.

Detection of BaP in seawater based on multi-walled carbon nanotubes composites immunosenor

Benzo(a)pyrene, as the main polycyclic aromatic hydrocarbon pollutant in marine oil spill pollution, has negative effects on marine ecology and human health. A facile and sensitive method of rapid benzo(a)pyrene detection in seawater is essential for marine conservation. In this paper, a novel immunosensor is fabricated using a multi-walled carbon nanotubes-chitosan composite loaded with benzo(a)pyrene antibody. This immunosensor is based on a biosensing assay mechanism that uses multi-walled carbon nanotubes-chitosan composites as conductive mediators to enhance electron transfer kinetics. Then, potassium ferricyanide was used as an electrochemical probe to produce an electrochemical signal for the voltammetric behavior investigation of the immune response by differential pulse voltammetry. Under optimal experimental conditions, the peak current change was inversely proportional to the benzo(a)pyrene concentration in the range of 0.5 ng⋅ml−1 and 80 ng⋅ml−1 with a detection limit of 0.27 ng⋅ml−1. The immunosensor was successfully applied to assay BaP in seawater, and the recovery was between 96.6 and 100%, which exhibited a novel, sensitive and interference-resistant analytical method for real-time water environment monitoring. The results demonstrate that the proposed immunosensor has a great potential for application in the monitoring of seawater.

Multi-Redox Active Carbons and Hydrocarbons: Control of their Redox Properties and Potential Applications

Precise control over redox properties is essential for high-performance organic electronic devices such as organic batteries, electrochromic devices, and information storage devices. In this context, multi-redox active carbons and hydrocarbons, represented as C_x H_y molecules (x≥1, y≥0), are highly sought after, because they can switch between multiple redox states. Herein, we outline the redox properties of C_x H_y molecules as solutes and adsorbed species. Furthermore, the limitations of evaluating their redox properties and the possible solutions are summarized. Additionally, the theoretical capacity (mAh/g) and gravimetric energy density (Wh/kg) of secondary batteries were estimated based on the redox properties of 185 C_x H_y molecules, which have primarily been reported in the last decade. Among them, seven C_x H_y molecules were found to have the potential to surpass the energy density of LiNi_0.6 Mn_0.2 Co_0.2 O₂ /graphite batteries. The use of C_x H_y molecules in multielectrochromic devices and multi-bit memory is also explained. We believe that this review will encourage further utilization of C_x H_y molecules thereby promoting its applications in organic electronic devices.