Investigating layer-by-layer films of carbon nanotubes and nickel phthalocyanine towards diquat detection

The indiscriminate use of pesticides makes us susceptible to the toxicity of these chemical compounds, which may be present in high quantities in our food. It is crucial to develop inexpensive and rapid methods for determining these pesticides for government control or even for the general population. In this study, we investigated the fabrication of self-assembled LbL films using multi-walled carbon nanotubes (MWCNT) and nickel tetrasulphonated phthalocyanine (NiTsPc) as an electrochemical sensor for the herbicide Diquat (DQ). The Layer-by-Layer (LbL) assembly of the (MWCNT/NiTsPc) film was examined, along with its structural and morphological characteristics. The effect of the number of layers in DQ detection was evaluated by cyclic voltammetry, followed by the detection through differential pulse voltammetry. The achieved limit of detection was 9.62 × 10-7 mol L-1. A ~ 30% decrease in sensitivity was observed in the presence of Paraquat, a banned herbicide and electrochemical interferent due to the structural similarities, which is regularly neglected in the most published studies. The sensor was tested in real samples, demonstrating a recovery of 98.5% in organic apples.

FIA- spectrophotometric method for the determination of amoxicillin in pharmaceuticals; application of AES, GAPI, and AGREE greenness assessment tools

A new, simple, and sensitive FIA-spectrophotometric method has been developed for evaluating pure amoxicillin and pharmaceutical formulations. The FIA method involves the reaction of dapsone with sodium nitrite and hydrochloric acid. Subsequently, the diazotized dapsone is coupled with amoxicillin in an alkaline medium, resulting in a stable orange dye with a maximum wavelength of 440 nm. The developed method was validated according to the ICH guidelines and found to have a concentration range of 1-150 µg/mL, a correlation coefficient of 0.9994, a molar extinction coefficient of 0.273 × 104 L/mol.cm, and a detection limit of 0.074 µg/mL. The FIA method was then evaluated using AES, GAPI, and AGREES analytical greenness assessment tools. The FIA method uses dapsone as an eco-friendly reagent, in addition to the FIA method's advantages of reduced sample and reagent usage, reduced waste generation, and cheaper equipment. So, it has been proposed as an excellent eco-friendly method for the determination of AMX in pharmaceutical formulations.

Application of molecular imprinting technology based on new nanomaterials in adsorption and detection of fluoroquinolones

Irrational use of fluoroquinolones (FQs) can lead to allergic reactions, adverse reactions to the heart and damage of the liver; thus, it is of great significance to establish rapid, sensitive and accurate detection methods for FQs. Molecularly imprinted polymers (MIPs) with specific structures synthesized by molecular imprinting technology (MIT) are widely used for the detection of FQs due to their high specificity, high sensitivity and stable performance. Recently, new functional nanomaterials with different morphologies and sizes, which can provide rich sites for surface chemical reactions, have attracted more and more attention of the researchers. Thus, the application status and development prospects of MIT based on new nanomaterials in the adsorption and detection of FQs were summarized in this study, providing a theoretical basis and technical guarantee for the development of new and efficient food safety analysis strategies based on MIPs.

Development of enzyme linked immunosorbent assay and lateral flow immunoassay for the rapid detection of dapsone in milk

High-throughput rapid detection of dapsone in milk without pretreatment.