Molecule-gated surface chemistry of Pt nanoparticles for constructing activity-controllable nanozymes and a three-in-one sensor. Issue 4 (23rd December 2019)

• Record Type: Journal Article
• Authors: Gao, Min; An, Pengli; Rao, Honghong; Niu, Zhengrong; Xue, Xin; Luo, Mingyue; Liu, Xiuhui; Xue, Zhonghua; Lu, Xiaoquan
• Is Part Of: Analyst. Volume 145:Issue 4(2020)
• Page Start: 1279
• Page End: 1287
• Publication Date: 2019-12-23
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/c9an01956a
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : A new surface chemistry-based modulation for constructing activity-controllable Pt nanoparticle nanozymes and their application in the development of a triple signal readout-based three-in-one sensor for Cu 2+ determination. Abstract : Herein, a simple strategy for constructing activity-controllable nanozymes is proposed based on the glutathione (GSH)-gated surface chemistry of citrate-capped Pt nanoparticles (PtNPs). PtNPs have been shown to have oxidase-like activity that can effectively catalyze the oxidation of 3, 3′, 5, 5′-tertamethylbenzidine (TMB) by O2, resulting in a typical color reaction from colorless to blue. We found that GSH can inhibit the oxidase-like activity of PtNPs as a molecule-gated surface chemistry element, resulting in a dramatic decrease of the oxidation of TMB. The addition of copper ions (Cu 2+ ) could oxidize GSH into glutathione disulfide (GSSG), resulting in the distinct suppression of GSH-modulated PtNP surface chemistry and oxidase-like activity inhibition, which further results in a significant acceleration of TMB oxidation and the obvious recovery of intense blue color. Furthermore, the color-based detection signal associated with the redox of TMB indicator here was found to show good fluorescence and a photothermal effect and exhibit sensitive and selective response toward the proposed molecule-gated surface chemistry and Cu 2+ target. On the basis of this phenomenon, we successfully constructed a three-in-one sensor for Cu 2+ with a triple signal readout, colorimetric, photothermal (temperature), and fluorescence, depending on the proposed in situ modulation method for PtNP catalysis. The applicability of the three-in-one sensor was also demonstrated by measuring Cu 2+ in human serum with a standard addition method, and the results are of satisfactory accuracy as confirmed by ICP-MS measurements.