Quantum Dots Based Mesoporous Structured Imprinting Microspheres for the Sensitive Fluorescent Detection of Phycocyanin

Abstract

Phycocyanin with important physiological/environmental significance has attracted increasing attention; versatile molecularly imprinted polymers (MIPs) have been applied to diverse species, but protein imprinting is still quite difficult. Herein, using phycocyanin as template via a sol−gel process, we developed a novel fluorescent probe for specific recognition and sensitive detection of phycocyanin by quantum dots (QDs) based mesoporous structured imprinting microspheres (SiO 2 @QDs@ms-MIPs), obeying electron-transfer-induced fluorescence quenching mechanism. When phycocyanin was present, a Meisenheimer complex would be produced between phycocyanin and primary amino groups of QDs surface, and then the photoluminescent energy of QDs would be transferred to the complex, leading to the fluorescence quenching of QDs. As a result, the fluorescent intensity of the SiO 2 @QDs@ms-MIPs was significantly decreased within 8 min, and accordingly a favorable linearity within 0.02−0.8 μM and a high detectability of 5.9 nM were presented. Excellent recognition specificity for phycocyanin over its analogues was displayed, with a high imprinting factor of 4.72. Furthermore, the validated probe strategy was successfully applied to seawater and lake water sample analysis, and high recoveries in the range of 94.0−105.0% were attained at three spiking levels of phycocyanin, with precisions below 5.3%. The study provided promising perspectives to develop fluorescent probes for convenient, rapid recognition and sensitive detection of trace proteins from complex matrices, and further pushed forward protein imprinting research.

Molecular imprinting: perspectives and applications

“…Segment imprinting has broadened the fields of MIPs for a number of target molecules including highly toxic, expensive compounds and biological macromolecules, which can be hardly utilized as the templates or cannot be easily imprinted. 158 174 developed QD based mesoporous structurally imprinted microspheres for specific recognition and sensitive detection of phycocyanin by the electron-transfer-induced fluorescence quenching mechanism. As a result, a favorable linearity and a high detectability were observed and the facile preparation and fluorescence sensing processes of QDs-MIPs are schematically displayed in Fig.…”

“…Also, providing mesoporous structures in the MIPs is another effective method. Accordingly, Chen's group 174 developed a novel imprinting fluorescent probe for specific recognition and sensitive detection of phycocyanin (PC) through the electron-transfer-induced fluorescence quenching mechanism between QDs and mesoporous structured microspheres (SiO 2 @QDs@ms-MIPs). The use of mesoporous silica structured MIP materials as selective recognition units and QDs as fluorescence detection units improved greatly sensitivity, response time, binding capacity and selectivity because of a large pore volume and the nanosized pore wall thickness of the mesoporous structure and the strong fluorescent signal of QDs.…”

A molecular imprinting-based turn-on Ratiometric fluorescence sensor for highly selective and sensitive detection of 2,4-dichlorophenoxyacetic acid (2,4-D)

“…It is considered to be an efficient way to develop MIP-based fluorescence sensors, which will combine the advantages of high selectivity of MIPs recognition and high sensitivity of fluorescence detection (Vinayaka et al, 2009;Wu et al, 2015;Zhang et al, 2015b). To date, most of the sensors are focused on fluorescence turn off, in which the fluorescence signal is diminished in the presence of the target analyte (Wu et al, 2015;Zhang et al, 2015b). Turn on fluorescence strategy is less commonly reported, but it is highly attractive because of the improved sensitivity by the enhancement of a fluorescence signal.…”

Fluorescence Probe Based on Hybrid Mesoporous Silica/Quantum Dot/Molecularly Imprinted Polymer for Detection of Tetracycline

“…[19][20][21][22][23] As new fluorescent materials, quantum dots (QDs) have greatly drawn the attention of researchers because of their advantages such as narrow and symmetric emission spectrum, large Stokes shift, low background noise, etc. [24][25][26] Some researchers have reported the application of MIPs in fluorescence sensors. [27][28][29] For fluorescence detection systems, the introduction of QDs capped by MIPs can clearly improve the selectivity and sensitivity.…”