Detection of Trace Hg(II) in Cosmetics and Aqueous Solution by a Gold Nanospikes Electrochemical Sensor

Abstract

An ultrasensitive and rapid electrochemical detection of trace Hg(II) sensor was developed. The significantly amplified electrochemical signals was caused by the high specific surface area of the electrochemical sensor. Scanning electron microscopy showed that the gold nanospikes were 200 ∼ 300 nm in length and 50 nm in diameter. The electrochemical properties of sensor were characterized by square wave voltammetry. Experimental parameters were optimized using square wave stripping voltammetry. The linear range of sensor for Hg(II) is 3 × 10−10 mol l−1 ∼ 7 × 10−7 mol l−1 and the limit of detection is 1 × 10−10 mol l−1. Hg(II) was successfully quantified in river water and cosmetics. The original Hg(II) in loose powder, Sunblock and whitening lotion using the high ratio surface area electrochemical sensor determination were found to be 2.234, 2.056 and 2.347 mg kg−1 respectively. The results are within the range of standard values, the RSD are 1.7%, 1.5% and 2.1%, respectively. HRSA Au electrode sensor displays high sensitive, excellent stability, reproducibility, especially more convenient than ICP-MS and AFS verification methods. We look forward to the possibility that the HRSA Au electrode sensor can be used for real-time monitoring of Mercury ions in water and cosmetics in the future.