Colorimetric detection of Cr (VI) based on the leaching of gold nanoparticles using a paper-based sensor

• Published in: Talanta (Oxford) 2016-12, Vol.161, p.819-825
• Main Authors: Guo, Jian-feng, Huo, Dan-qun, Yang, Mei, Hou, Chang-jun, Li, Jun-jie, Fa, Huan-bao, Luo, Hui-bo, Yang, Ping
• Format: Article
• Language: English
• Subjects: Colorimetric; Cr (VI); Gold nanoparticles; Non-aggregation; Paper-based
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2016.09.032

Herein, we have developed a simple, sensitive and paper-based colorimetric sensor for the selective detection of Chromium (Ⅵ) ions (Cr (VI)). Silanization-titanium dioxide modified filter paper (STCP) was used to trap bovine serum albumin capped gold nanoparticles (BSA-Au NPs), leading to the fabrication of BSA-Au NPs decorated membrane (BSA-Au NPs/STCP). The BSA-Au NPs/STCP operated on the principle that BSA-Au NPs anchored on the STCP were gradually etched by Cr (VI) as the leaching process of gold in the presence of hydrobromic acid (HBr) and hence induced a visible color change. Under optimum conditions, the paper-based colorimetric sensor showed clear color change after reaction with Cr (VI) as well as with favorable selectivity to a variety of possible interfering counterparts. The amount-dependent colorimetric response was linearly correlated with the Cr (VI) concentrations ranging from 0.5µM to 50.0µM with a detection limit down to 280nM. Moreover, the developed cost-effective colorimetric sensor has been successfully applied to real environmental samples which demonstrated the potential for field applications. [Display omitted] •A functional paper-based sensor was designed to detect Cr (VI) based on the leaching of gold nanoparticles.•Detection limit for Cr (VI) was as low as 280nM with a wide linear range (0.5nM–50µM).•The proposed sensor showed high resistance to the interference ions.