Glass substrates crosslinked with tetracycline-imprinted polymeric silicate and CdTe quantum dots as fluorescent sensors

A fluorescence-based sensor that combines the merits of quantum dots (QDs) and molecularly imprinted polymers (MIPs) was first fabricated on a glass substrate via a solegel route. Some of the key performance factors, including silane selection, substrate etching, the reaction times of glass silanization and solegel polymerization, and the times and methods used for template stripping and loading, were discussed and determined. After fabricating the sensor on either a 3-aminopropyltriethoxysilane (APS) or a 3-mercaptopropyltriethoxysilane (MPS) modified glass substrate, APS showed a much better performance than MPS as both the capping reagent of QDs and the functional monomer of tetracyclinetemplated MIPs. The APS-QDs on APS-modified glass had a higher imprinted factor (IF = 5.6), a lower LOD (2.1 mu M, 3 sigma), and a more stable signal (2.8%, n = 10 at 70 mu M) than those on the MPS-modified glass (IF = 5.2, LOD = 6.5 mu M, stability = 6.2%). Furthermore, the recoveries of tetracycline (70 mu M) from BSA (133 mu g/mL) and FBS (0.66 ppt) by the APS-modified glass were 98% (RSD = 3.5%, n = 5) and 97% (RSD = 5.7%), respectively. For the MPS-modified glass, recoveries of 95% (RSD = 7.2%) and 89% (RSD = 8.7%) were observed at 67 mg/mL of BSA and 0.33 ppt of FBS, respectively. (C) 2016 Elsevier B.V. All rights reserved.