Ultrasensitive and recyclable superstructure of AuSiO2@Ag wire for surface-enhanced Raman scattering detection of thiocyanate in urine and human serum
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CitationAnkudze, Bright. Philip, Anish. Pakkanen, Tuula T. (2019). Ultrasensitive and recyclable superstructure of AuSiO2@Ag wire for surface-enhanced Raman scattering detection of thiocyanate in urine and human serum. Analytica Chimica Acta, 1049, 179-187. 10.1016/j.aca.2018.10.040.
Thiocyanate level in the human system can serve as a biomarker to distinguish smokers from non-smokers. Thiocyanate is a potential goitrogen, thus an accurate determination may help to identify lactating mothers with high thiocyanate dosage, thereby preventing the transport of excess SCN− to infants. Surface-enhanced Raman spectroscopy has become a versatile and reliable technique to detect SCN− in different media. However, the conventional surface-enhanced Raman scattering (SERS) substrates used to detect SCN− are often discarded after use. The frequent disposal of such metal nanoparticles is detrimental to the environment and makes the SERS-based detection of SCN− uneconomical. In this study, we present fabrication of a new, ultrasensitive and recyclable SERS substrate, based on an AuSiO2@Ag wire (W) superstructure, to detect SCN− in different media. The hierarchical AuSiO2@AgW substrate was obtained by forming nano-sized patches of SiO2 on micron-sized AgW and anchoring 30 nm-sized gold nanoparticles on the patches with mercaptopropyltrimethoxysilane. This ultrasensitive substrate could detect SCN− at a low concentration of 0.001 μM in water, and 0.01 μM in urine and human serum. In addition, a facile procedure to regenerate and recycle the SCN− bound AuSiO2@AgW platform in different media has been demonstrated. The insight gained in the present study can serve as a promising and powerful method for fabrication of active and recyclable substrates for SERS-based detection of SCN−.