Target-induced nanocatalyst deactivation facilitated by core@shell nanostructures for signal-amplified headspace-colorimetric assay of dissolved hydrogen sulfide.
Colorimetric assay platforms for dissolved hydrogen sulfide (H2S) have been developed for more than 100 years, but most still suffer from relatively low sensitivity. One promising route out of this predicament relies on the design of efficient signal amplification methods. Herein, we rationally designed an unprecedented H2S-induced deactivation of (gold core)@(ultrathin platinum shell) nanocatalysts (Au@TPt-NCs) as a highly efficient signal amplification method for ultrasensitive headspace-colorimetric assay of dissolved H2S. Upon target introduction, Au@TPt-NCs were deactivated to different degrees dependent on H2S levels, and the degrees could be indicated by using a Au@TPt-NCs-triggered catalytic system as a signal amplifier, thus paving a way for H2S sensing. The combination of experimental studies and density functional theory (DFT) studies revealed that the Au@TPt-NCs with only 2-monolayer equivalents of Pt (θPt = 2) were superior for H2S-induced nanocatalyst deactivation owing to their enhanced peroxidase-like catalytic activity and deactivation efficiency stemmed from the unique synergistic structural/electronic effects between Au nanocores and ultrathin Pt nanoshells. Importantly, our analytical results showed that the designed method was indeed highly sensitive for sensing H2S with a wide linear range of 10-100 nM, a slope of 0.013 in the regression equation, and a low detection limit of 7.5 nM. Also the selectivity, reproducibility, and precision were excellent. Furthermore, the method was validated for the analysis of H2S-spiked real samples, and the recovery in all cases was 91.6-106.7%. With the merits of high sensitivity and selectivity, simplification, low cost, and visual readout with the naked eye, the colorimetric method has the potential to be utilized as an effective detection kit for point-of-care testing.
Institute of Nanomedicine and Nanobiosensing, Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Department of Chemistry, Fuzhou University , Fuzhou 350108, P. R. China.
Zhuangqiang
Z
Gao
Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences , Chongqing 402160, P. R. China.
Dianyong
D
Tang
Institute of Nanomedicine and Nanobiosensing, Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Department of Chemistry, Fuzhou University , Fuzhou 350108, P. R. China.
Dianping
D
Tang
Chair for Analytical Chemistry, Institute of Hydrochemistry, Technische Universität München , Marchioninistrasse 17, D-81377 München, Germany.
Reinhard
R
Niessner
Chair for Analytical Chemistry, Institute of Hydrochemistry, Technische Universität München , Marchioninistrasse 17, D-81377 München, Germany.
Dietmar
D
Knopp
D000818:Animals; D002384:Catalysis; D002417:Cattle; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006862:Hydrogen Sulfide / Q000032:analysis* / Q000097:blood*; D057230:Limit of Detection; D008958:Models, Molecular; D057145:Nanoshells / Q000737:chemistry* / Q000648:ultrastructure; D010984:Platinum / Q000737:chemistry*; D015203:Reproducibility of Results; D014867:Water / Q000032:analysis*
D014867:Water; D010984:Platinum; D006046:Gold; D006862:Hydrogen Sulfide