Colorimetric and electrochemical sensing of As(III) using calix[4]pyrrole capped gold nanoparticles and evaluation of its cytotoxic activity

Ultrasensitive and selective colorimetric and smartphone-based detection of arsenic ions in aqueous solution using alliin-chitosan-AgNPs

In this study, we developed a highly selective and sensitive colorimetric sensor for arsenic [As(iii)] detection using alliin-chitosan-stabilized silver nanoparticles (AC-AgNPs). The AC-AgNPs were synthesized using a complex prepared by mixing aqueous garlic extract containing alliin and chitosan extracted from shrimp. The synthesis of AC-AgNPs was confirmed by UV-vis spectroscopy, which showed a surface plasmon resonance (SPR) band at 403 nm, and TEM analysis revealing spherical nanoparticles with a mean diameter of 7.57 ± 3.52 nm. Upon the addition of As3+ ions, the brownish-coloured solution of AC-AgNPs became colourless. Moreover, the computational study revealed that among all the metal ions, only As3+ was able to form a stable complex with AC-AgNPs, with a binding energy of 8.7 kcal mol-1. The sensor exhibited a linear response to As(iii) concentrations ranging from 0.02 to 1.4 fM, with a detection limit of 0.023 fM. The highest activity was observed at pH 7 and temperature 25 °C. Interference studies demonstrated high selectivity against common metal ions. The study also demonstrated that the concentration of As3+ ions can be estimated by the decrease in red intensity and increase in green intensity in smartphone optical transduction signals. These results indicate the potential of the AC-AgNP-based sensor for reliable and efficient arsenic detection in environmental monitoring.

Nanomaterial-based optical colorimetric sensors for rapid monitoring of inorganic arsenic species: a review

Health concerns about the toxicity of arsenic compounds have therefore encouraged the development of new analytical tools for quick monitoring of arsenic in real samples with improved sensitivity, selectivity, and reliability. An overview of advanced optical colorimetric sensor techniques for real-time monitoring of inorganic arsenic species in the environment is given in this review paper. Herein, several advanced optical colorimetric sensor techniques for arsenite (As+3) and arsenate (As+5) based on doping chromogenic dyes/reagents, biomolecule-modified nanomaterials, and arsenic-binding ligand tethered nanomaterials are introduced and discussed. This review also highlights the benefits and limitations of the colorimetric sensor for arsenic species. Finally, prospects and future developments of an optical colorimetric sensor for arsenic species are also proposed. For future study in this sector, particularly for field application, authors recommend this review paper will be helpful for readers to understand the design principles and their corresponding sensing mechanisms of various arsenic optical colorimetric sensors.

Advances in Electrochemical Detection Electrodes for As(III)

Arsenic is extremely abundant in the Earth's crust and is one of the most common environmental pollutants in nature. In the natural water environment and surface soil, arsenic exists mainly in the form of trivalent arsenite (As(III)) and pentavalent arsenate (As(V)) ions, and its toxicity can be a serious threat to human health. In order to manage the increasingly serious arsenic pollution in the living environment and maintain a healthy and beautiful ecosystem for human beings, it is urgent to conduct research on an efficient sensing method suitable for the detection of As(III) ions. Electrochemical sensing has the advantages of simple instrumentation, high sensitivity, good selectivity, portability, and the ability to be analyzed on site. This paper reviews various electrode systems developed in recent years based on nanomaterials such as noble metals, bimetals, other metals and their compounds, carbon nano, and biomolecules, with a focus on electrodes modified with noble metal and metal compound nanomaterials, and evaluates their performance for the detection of arsenic. They have great potential for achieving the rapid detection of arsenic due to their excellent sensitivity and strong interference immunity. In addition, this paper discusses the relatively rare application of silicon and its compounds as well as novel polymers in achieving arsenic detection, which provides new ideas for investigating novel nanomaterial sensing. We hope that this review will further advance the research progress of high-performance arsenic sensors based on novel nanomaterials.

A versatile enrichment of functionalized calixarene as a facile sensor for amino acids

Amino acids have become the most important part of the human biological system due to their roles in the living processes. Role of amino acids stretches beyond their traditional role as a building block for proteins, deficiency of the same could lead to decreased immunity, digestive problems, depression, fertility issues, lower mental alertness, slowed growth in children, and many other health issues. The acute detection of amino acids is necessary to determine the human health domain. Here in this review, we summarize and study the calixarenes as a complex detailed being of an immeasurable value and its utilization for the amino acids' detection. The key factors responsible such as noncovalent forces, LOD and supramolecular chemistry of calixarenes with amino acids are described well. This study presents the most recent efforts made for the development of potential and highly efficient calixarene based sensors for the detection of amino acids.

Recent developments in calix[4]pyrrole (C4P)-based supramolecular functional systems

Recent advances with calix[4]pyrrole-based supramolecular functional entities in the fields of molecular recognition (receptors, sensors, and metal ion caged systems), self-assembly (polymers), photo/pH-responsive molecular switches and catalysis are reviewed.