posted on 2023-11-30, 21:04authored byZhiyang Zhang, Meichun Liu, Yanzhou Wu, Yanhui Zhang, Yan Chen, Ji Qi, Jianping Wang, Jinmao You, Lingxin Chen
The use of chemical sensors for the detection of Ag(I)
ions under
a chloride (Cl–) environment is extremely difficult
due to the chloride masking effect. Herein, a surface-enhanced Raman
scattering (SERS) nanosensor using p-aminothiophenol
(PATP) as probe molecules has been developed for the detection of
Ag(I) ions under high concentrations of Cl– ions.
The peak intensity ratio I438/I390 was used as the basis for the quantitative
analysis, showing a high selectivity for Ag(I) ions. Corroborating
with DFT simulations, the origin of the sensing mechanism is the existence
of coordination between Ag(I) ions and PATP. To enhance the sensitivity
of the SERS nanosensors, we propose a sequence-dependent probe modification
method by decreasing the Raman signal from the isolated probe molecules
in the nanogaps of nanoparticles. More significantly, this breakthrough
SERS sensor addresses a long-standing issue of conventional Ag(I)
sensors for the detection of total Ag(I) ions under a high-chloride
environment. Even at ultrahigh concentrations (up to 500 mM) of Cl– ions, this method still breaks the chloride masking
effect and exhibits outstanding sensitivity with a limit of detection
(LOD) of 0.07 μM for Ag(I) ions. In addition, the successful
detection of Ag(I) ions in the real samples with Cl– ions indicates that our method has promise for practical applications.
These findings have significant implications for future research on
heavy-metal analysis in complex samples.