Rapid detection of paraquat residues in fruit samples using mercaptoacetic acid functionalized Au@AgNR SERS substrate

• Published in: Microchemical journal 2023-06, Vol.189, p.108558, Article 108558
• Main Authors: Lv, Mingchun, Hussain, Nisar, Sun, Da-Wen, Pu, Hongbin
• Format: Article
• Language: English
• Subjects: Core–shell nanorods; Fruit; Herbicide; Residual assessment; SERS substrate
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2023.108558

[Display omitted] •Mercaptoacetic acid functionalized coreshell nanorods (MAA/Au@AgNRs) were prepared.•Proposed MAA/Au@AgNRs demonstrated excellent SERS enhancement and sensitivity.•MAA/Au@AgNRs showed better stability compared with unmodified Au@AgNRs.•MAA/Au@AgNRs were successfully used to detect residues of paraquat in fruit samples. An optimum SERS performance is mainly dependent on the development of innovative substrates that show high spectral reproducibility and stability. The current study involves the synthesis of core–shell nanorods (Au@AgNRs) functionalized with mercaptoacetic acid (MAA) to increase the stability and sensitivity of the substrate for cost-effective and sensitive assessment of paraquat (PQ) residues in fruit samples. The morphological analysis of the substrate using TEM and STEM-EDS images indicated the uniformity in size and structure of the prepared nanoparticles. Further the modified substrate, MAA/Au@AgNRs showed excellent stability and sensitivity in comparison with its unmodified counterpart. For the evaluation of PQ residues in pear and apple fruit samples the modified substrate exhibited R2 values of 0.9954 and 0.9914 with a low limit of detections of 0.012 and 0.024 ppm, and good percent recoveries of 80–110 % and 81–104 %, respectively. Thus, the study proved the effectiveness of the proposed MAA/Au@AgNRs substrate for assessing residues of herbicide in complex foods.