Conjugated polymer with carboxylate groups-Hg2+ system as a turn-on fluorescence probe for label-free detection of cysteine-containing compounds

A Comprehensive Insight on the Health Benefits and Phytoconstituents of Camellia sinensis and Recent Approaches for Its Quality Control

Tea, Camellia sinensis, which belongs to the family Theaceae, is a shrub or evergreen tree up to 16 m in height. Green tea is very popular because of its marked health benefits comprising its anticancer, anti-oxidant, and antimicrobial activities, as well as its effectiveness in reducing body weight. Additionally, it was recognized by Chinese people as an effective traditional drink required for the prophylaxis against many health ailments. This is due to the complex chemical composition of green tea, which comprises different classes of chemical compounds, such as polyphenols, alkaloids, proteins, minerals, vitamins, amino acids, and others. The beneficial health effects of green tea ultimately led to its great consumption and increase its liability to be adulterated by either low-quality or non-green tea products with concomitant decrease in activity. Thus, in this review, green tea was selected to highlight its health benefits and phytoconstituents, as well as recent approaches for its quality-control monitoring that guarantee its incorporation in many pharmaceutical industries. More research is needed to find out other more biological activities, active constituents, and other simple and cheap techniques for its quality assurance that ascertain the prevention of its adulteration.

A Conjugated Polymer Fluorescent Sensor for Continuous Identification of Copper(II) and Pyrophosphate in Blood Serum and Synovial Fluid

A novel "on-off-on" super-sensitive conjugated polymer fluorescence sensor (PPE-DPA) was developed and it was applied to realize the continuous recognition of Cu²⁺ and pyrophosphate (PPi). The fluorescence intensity decreased linearly with the change of Cu²⁺ from 0.05 to 5.0 μmol L^-1 and the limit of detection was 24 nmol L^-1. The fluorescence intensity was linearly enhanced with the increase of PPi from 0.5 to 12.0 μmol L^-1 and the limit of detection was 230 nmol L^-1. In addition, this method was applied to detect PPi in the blood serum and synovial fluid of patients with arthritis and satisfactory results were obtained. Thus, the PPE-DPA is not only an effective tool for detecting Cu²⁺ and PPi in samples, but also presents a potential way to diagnose arthritis.

The development of unimolecular conjugated polymeric micelles for the highly selective detection and recovery of gold from electronic waste

Gold recycling is a sustainable development strategy that will save a large amount of carbon dioxide emissions. In this work, we have developed a conjugated polymer, that can not only detect Au content in e-waste but also extract Au from e-waste.

FeCo nanoparticles-embedded carbon nanofibers as robust peroxidase mimics for sensitive colorimetric detection of l-cysteine

A simple and low cost detection of l-cysteine is essential in the fields of biosensors and medical diagnosis. In this study, we have developed a simple electrospinning, followed by calcination process to prepare FeCo nanoparticles embedded in carbon nanofibers (FeCo-CNFs) as an efficient peroxidase-like mimic for the detection of l-cysteine. FeCo nanoparticles are uniformly dispersed within CNFs, and their diameters are highly influenced by the calcination temperature. The calcination temperature also influences the peroxidase-like catalytic activity, and the maximum activity is achieved at a calcination temperature of 550 °C. Owing to the high catalytic activity of the as-prepared FeCo-CNFs, a colorimetric technique for the rapid and accurate determination of l-cysteine has been developed. The detection limit is about 0.15 μM with a wide linear range from 1 to 20 μM. In addition, a high selectivity for the detection of l-cysteine over other amino acids, glucose and common ions is achieved. This study provides a simple, rapid and sensitive sensing platform for the detection of l-cysteine, which is a promising candidate for potential applications in biosensing, medicine, environmental monitoring.