A tailored dual core-shell magnetic SERS substrate with precise shell-thickness control for trace organophosphorus pesticides residues detection

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 316; p. 124336
• Main Authors: Lv, Mingchun, Pu, Hongbin, Sun, Da-Wen
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.08.2024
• Subjects: Adsorption; Controllable thickness; Fenthion - analysis; Food Contamination - analysis; Gold - chemistry; Limit of Detection; Organophosphorus Compounds - analysis; Organophosphorus Compounds - chemistry; Organophosphorus pesticides; Organothiophosphates - analysis; Pesticide Residues - analysis; SERS substrate Fe3O4-COOH@UiO-66/Au@Ag; Silver - chemistry; Spectrum Analysis, Raman - methods; Tailored Au@Ag; Triazoles - analysis; Triazoles - chemistry; UiO-66 shell; Vegetables - chemistry; SERS substrate Fe3O4-COOH@UiO-66/Au@Ag; UiO-66 shell; Organophosphorus pesticides; Controllable thickness; Tailored Au@Ag; SERS substrate FeO-COOH@UiO-66/Au@Ag
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2024.124336

[Display omitted] •A novel tailored dual core–shell magnetic SERS substrate FCUAA was synthesized.•A water-assisted layer-by-layer growth method for the UiO-66 shell was explored.•Precise regulation of the shell thickness at the nanoscale was achieved.•The SERS substrate demonstrated a high SERS response to fenthion and triazophos.•The FCUAA exhibited low LODs for the OPs residues. For addressing the challenges of strong affinity SERS substrate to organophosphorus pesticides (OPs), herein, a rapid water-assisted layer-by-layer heteronuclear growth method was investigated to grow uniform UiO-66 shell with controllable thickness outside the magnetic core and provide abundant defect sites for OPs adsorption. By further assembling the tailored Au@Ag, a highly sensitive SERS substrate Fe3O4-COOH@UiO-66/Au@Ag (FCUAA) was synthesized with a SERS enhancement factor of 2.11 × 107. The substrate's suitability for the actual vegetable samples (cowpeas and peppers) was confirmed under both destructive and non-destructive detection conditions, showing a strong SERS response to fenthion and triazophos, with limits of detection of 1.21 × 10-5 and 2.96 × 10-3 mg/kg in the vegetables under destructive conditions, and 0.13 and 1.39 ng/cm2 for non-destructive detection, respectively. The FCUAA substrate had high SERS performance, effective adsorption capability for OPs, and demonstrated good applicability, thus exhibiting great potential for rapid detection of trace OPs residues in the food industry.