Ultrasensitive turn on molecularly imprinted fluorescence sensor for glycoprotein detection based on nanoparticles signal amplification

Abstract

In this work, we proposed a “turn on” molecularly imprinted fluorescence sensor (MIFS) for ultrasensitive detection of glycoprotein using horseradish peroxidase (HRP) as a model target based on nanoparticles signal amplification. Boronic acid modified magnetic nanoparticles were employed as supporting matrix for HRP imprinting by surface oriented imprinting strategy. Boronic acid modified tetra(4-carboxyphenyl) porphyrin nanoparticles (BA-TCPP NPs) as signal tag were captured by imprinted magnetic nanoparticles in the presence of HRP based on boronate affinity sandwich assay. The dissolution of TCPP NPs into thousands of porphyrin molecules resulted in amplified fluorescence signal detection of HRP. As a result, the MIFS could be applied in the detection of HRP in the linear range of 0.1 μg/L–10 mg/L with LOD of 0.042 μg /L (S/N = 3). Due to the high selectivity of molecular imprinting technique, the high affinity of bononic acid with glycoprotein, and the high sensitivity of nanoparticles signal amplification, the sensitivity of the “turn on” MIFS was two orders of magnitude higher than traditional “turn off” MIFS. The “turn on” MIFS were successfully applied to determine of HRP in urine samples with average recoveries ranging from 98 % to 104 % and RSD below 4.4 %.The results proved that signal amplification combined with boronate affinity sandwich assay was an effective method to construct MIFS with conspicuous sensitivity.