Warfarin

The thiolated aptamer was synthesized by Synbio Technologies (Shanghai, China), the sequence of the aptamer was shown below: 5′-GATCGGGTGT GGGTGGCGTA AAGGGAGCAT CGGACA-3′, 5′-SH. OTA and OTB (analytical standard) used in this study was purchased from Pribolab Pte. Ltd. (Qingdao, China). Gold particles were synthesized from Chloroauric acid (HAuCl₄) and sodium citrate according to the literature [40 (link)].
Cysteamine (CA), Bovine serum protein (BSA), N-acetyl-l-phenylalanine (NAP), and Warfarin were purchased from Shanghai Yuanye Bio-technology Co. Ltd. (Shanghai, China). Potassium ferrocyanide (K₄[Fe(CN)₆]) and, potassium ferricyanide (K₃[Fe(CN)₆]), were purchased from Sinopharm Chemical Reagent Co. Ltd., Shanghai, China. The binding buffer (BB pH 7.4) was applied in all experiments containing 1 mM MgCl₂, 140 mM NaCl, 2.7 mM KCl, 0.1 mM Na₂HPO₄, and 1.8 mM KH₂PO₄ [28 (link)]. Ultra-pure water was obtained from a Milli-Q water-purification system (Millipore, Bedford, MA, USA).
An isolate H1 of Aspergillus niger isolated from the wine production region in Hexi Corridor, Gansu Province, which was provided by the College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China. The pathogen was grown on potato dextrose agar (PDA) medium for 7–10 days.

LDR (purity >98%), diclofenac (purity >99%), tolbutamide (purity >99%), warfarin (purity >98%), and chlorzoxazone (purity >98%) were obtained from Shanghai Yuanye Biological Technology Co., Ltd. (Shanghai, China). Sodium carboxyl methyl cellulose (CMC-Na) was purchased from Tianjin Damao Chemical Reagent Factory (Tianjin, China). Ethylenediaminetetraacetic acid disodium salt (EDTA-Na₂) was purchased from Beijing Solarbio Science and Technology Co., Ltd. (Beijing, China). Methanol and acetonitrile of LC-MS grade were obtained from Sigma-Aldrich (St. Louis, MO). Formic acid of LC-MS grade was purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China).