title: Comparative syntheses of tetracycline-imprinted polymeric silicate and acrylate on CdTe quantum dots as fluorescent sensors.
abstract: The amphoteric drug molecule tetracycline, which contains groups with pKa 3.4-9.9, was used as a template for conjugating molecularly imprinted polymers (MIPs) and as a quencher for CdTe quantum dot (QD) fluorescence. Two MIP-QD composites were synthesized by a sol-gel method using a silicon-based monomer and a monomer linker between the MIP and QD, i.e., tetraethoxylsilane/3-mercaptopropyltriethoxysilane (MPS) and tetraethoxylsilane/3-aminopropyltriethoxysilane (APS). Another MIP-QD composite was synthesized by the chain-growth polymerization of methacrylic acid (MAA) and an allyl mercaptan linker. The prepared MIP-QDs were characterized by FTIR and SEM and utilized at 0.33 mg/mL to determine the tetracycline content in phosphate buffers (pH 7.4, 50mM) through the Perrin and Stern-Volmer models of quenching fluorometry. The Perrin model was applied to tetracycline concentrations of 7.4 μM-0.37 mM for MIP-MPS-QD, 7.4 μM-0.12 mM for MIP-APS-QD, and 7.4 μM-0.10mM for MIP-MAA-QD (R(2)=0.9988, 0.9978, and 0.9931, respectively). The Stern-Volmer model was applied to tetracycline concentrations of 0.12-0.37 mM for MIP-APS-QD (R(2)=0.9983) and 0.10-0.37 mM for MIP-MAA-QD (R(2)=0.9970). The detection limits were 0.45 μM, 0.54 μM, and 0.50 μM for MIP-MPS-QD, MIP-APS-QD, and MIP-MAA-QD, respectively. Equilibrium times, differences between imprinted and nonimprinted polymers, and MIP-QD quenching mechanisms were discussed. Finally, specificity studies demonstrated that MIP-MAA-QD exhibited optimal recoveries of 96% from bovine serum albumin (n=5, RSD=3.6%) and 91% from fetal bovine serum (n=5, RSD=4.8%).
authors.affiliation: Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan; Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan.
authors.forename: Mu-Rong
authors.initials: MR
authors.lastname: Chao
authors.affiliation: Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan; Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan.
authors.forename: Chiung-Wen
authors.initials: CW
authors.lastname: Hu
authors.affiliation: School of Pharmacy, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan. Electronic address: cjl@mail.cmu.edu.tw.
authors.forename: Jian-Lian
authors.initials: JL
authors.lastname: Chen
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods; D019187:Cadmium Compounds / Q000737:chemistry*; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry*; D005470:Fluorometry / Q000379:methods; D057230:Limit of Detection; D054802:Molecular Imprinting; D044367:Phase Transition; D045663:Quantum Dots / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry*; D013752:Tetracycline / Q000032:analysis*
chemical_list: D000179:Acrylates; D000900:Anti-Bacterial Agents; D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D012710:Serum Albumin, Bovine; D013752:Tetracycline; C036658:acrylic acid; D013691:Tellurium; C028337:cadmium telluride
keywords: Molecularly imprinted polymers; Polyacrylate; Quantum dot; Sol-gel; Tetracycline