Fabrication of liquid-liquid self-assembled Ag arrays on disposable screen-printed electrodes and their application in the identification and analysis of the adsorption behavior of organic carboxylates through in situ electrochemical surface-enhanced Raman scattering

A disposable Ag array@screen-printed electrode (SPE) was fabricated for the identification and analysis of the adsorption behavior of organic carboxylates in in situ electrochemical surface-enhanced Raman scattering (EC-SERS). Liquid-liquid self-assembled Ag arrays were prepared and modified onto the SPE to induce the SERS enhancement effect. The Ag arrays were characterized by transmission electron microscopy and UV-Vis spectroscopy and the SERS performance of the sensor was explored. The adsorption behavior and orientation of citrate, tartrate, and malate on the Ag array@SPEs at controlled potential for appropriate durations were studied. The results showed that citrate, tartrate, and malate can be concentrated on the Ag array@SPE surface with an effective amplification of SERS signals at a potential of 0.100 V vs. Ag/AgCl for 400 s, 450 s and 350 s. Carboxylates were identified on the basis of the vibrational assignments of characteristic SERS bands. Citrate, tartrate and malate adsorbed mainly in claw, parallel and vertical forms on the sensor at controlled potential. Therefore, the Ag array@SPEs have potential applications in the rapid and sensitive determination of these analytes and the identification of intermediates in EC-SERS.