The identification of Chinese medicinal herbs occupies a crucial part in the development of the food and drug market. Although molecular identification based on real-time PCR offers good versatility and uniform digital standards compared with traditional methods, such as morphology, the dependence on large-scale equipment hinders spot detection and marketable applications. In this study, we developed a DNA nanoclaw for colorimetric detection and visible on-site identification of Chinese medicines. When specific miRNA is present, the DNAzyme is activated and cleaves the substrate strand, triggering the catalytic hairpin assembly (CHA) reaction and forming branched DNA junctions on AuNP-I. This can then capture AuNP-II through hybridization and facilitate their aggregation, resulting in a noticeable color change that is observable to the naked eye. By harnessing the dual amplification of DNAzyme and CHA, this highly sensitive nanoprobe successfully achieved specific identification of Chinese medicines. This offers a new perspective for on-site testing in the herbal market.
Chromium(VI) is proved to be highly carcinogenic and mutagenic, thus sensitive and rapid sensors for monitoring Cr(VI) are in urgent demand. In this work, a facile fluorescent assay for the sensitive and selective detection of Cr(VI) was proposed based on static quenching combined with inner filter effect (IFE) using phosphate functionalized carbon dots (PCDs) as nanoprobes. A good linear quenching was observed in the range of 1.0–400 μM with a detection limit of 0.24 μM (σ/S = 3) under the optimized conditions. The nanoprobe was employed for detecting Cr(VI) in real water samples including river water and tap water with satisfactory recovery. Moreover, with the addition of Cr(VI), the color changes of PCDs can be easily observed by the naked eye under a UV lamp. Based on this, Cr(VI) test papers were fabricated for spot quick detection of Cr(VI).
危险品化学品经营许可证（带存储）