A Wireless Magnetoelastic Sensor for Urinary 2-Naphthol Detection Based on the Precipitation of 2-Naphthol with Diazonium Salts

Abstract

A wireless magnetoelastic sensor has been developed for the determination of 2-naphthol (2-NAP) in human urine. This method is based on the precipitation of 2-NAP with diazonium salts produced by the diazo-reaction of sulfamethoxazole (SMZ) with nitrite under a weak alkaline condition, resulting in a descending of the resonance frequency of a wireless magnetoelastic sensor. The frequence shift values (ΔF) of the sensor were directly proportional to the concentration in the range of 1.13 -139 μmol L -1 for 2-NAP with a correlation coefficient of 0.997 and a detection limit of 0.340 μmol L -1 . The relative standard deviations were 2.38, 2.40 and 2.44%, and the average recovery was 107% (n = 6). The proposed method has additional advantages of being less time-consuming, low cost and remote query, and can be applied for realtime and in situ monitoring of 2-NAP in human urine. It would be a benefit to extend the scope of applications of magnetoelastic sensing techniques.

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“…Fortunately, the wireless magnetoelastic sensors (WMS) have been developed for detecting Staphylococcus [12], Escherichia coli O157:H7 [13], breast cancer cell [14], and so on. These sensors have some noteworthy advantages of being low cost, remote query and high sensitivity [15][16][17]. Nanomaterials such as graphene oxide (GO) have attracted much interest recently [18][19][20][21][22].…”