Preparation of co-enhanced gold nanoclusters and its application in the detections of 4-hexylresorcinol and Cr6+

Abstract

A water-soluble, stable, simple, and dual ligands (bovine serum albumin and lysozyme) and Ag doping co-enhanced Au nanoclusters (Lys/BSA-Ag/AuNCs) was synthesized by one-step wet chemical synthesis. The introduction of Lys-and Ag could improve significantly the quantum yields of AuNCs (QYs, 2.54% to 12.73%). A new ratio fluorescent probe (RF-probe) was successfully obtained for sensitively and selectively mensurating 4-hexylresorcinol (4-HR) and Cr6+. That is, the fluorescence (FL) intensity of nanoclusters at 610 nm was used as the built-in reference, while dopamine (DA) reacting with 4-HR could produce a new fluorescent substance, and its FL intensities at 490 nm were enhanced gradually with increasing the concentrations of 4-HR. On the other hand, Cr6+ will react with DA and consume the amount of DA reacting with 4-HR, resulting in the weakening of FL intensity at 490 nm, so the ratiometric fluorescence detection of Cr6+ was also realized. The contents of 4-HR and Cr6+ could be monitored by the RF-probe with linear ranges of 1.0–140.0 and 3.0–110.0 nM, and corresponding values of LOD (limit of detection) were calculated to be 0.16 and 0.37 nM (3σ/slope). Moreover, the proposed method was extended to the detections 4-HR and Cr6+ in practical samples, and the results were consistent with those of the standard HPLC and UV–vis spectrophotometric methods. In addition, Lys/BSA-Ag/AuNCs exhibited an excellent temperature sensing performance in the range of 10.0–64.0 ℃.