Ultrasensitive and specific detection of glycoprotein with boronic acid-modified / fluorescein isothiocyanate-loaded graphene oxide as signal amplification matrix

Abstract

Here, integration of boronic acid-modified / fluorescein isothiocyanate-loaded graphene oxide (BFGO) and boronate-affinity-oriented surface imprinting magnetic nanoparticles (BSIMN) was proposed for ultrasensitive and specific detection of glycoprotein. The innovative BFGO, which was modified with boronic acid and loaded with generous fluorescein isothiocyanate, could selectively label glycoprotein by boronate-affinity and perform fluorescence signal amplification and output. In addition, the protein-free BFGO was fabricated entirely from chemicals and had fine hydrophilicity due to the modification of hydrophilic polyethylene glycol. Furthermore, the BSIMN possessed specific selectivity toward template glycoprotein because of boronate-affinity-related molecularly imprinted recognition. BSIMN linked BFGO (BSBF) for glycoprotein detection depended on a dual boronate-affinity synergy, in which glycoprotein was first selectivity captured by the BSIMN and then labeled with BFGO. The proposed BSBF strategy exhibited universal applicability, and provided ultrahigh sensitivity with limit of detection of 23 fg mL−1 and 1.2 fg mL−1 for horseradish peroxidase and carcinoembryonic antigen, respectively. Finally, the BSBF strategy was successfully used in detection of glycoprotein in spiked serum sample with recovery between 93.9 % and 106.8 %, and relative standard deviation no more than 7.0 %, respectively. Therefore, this novel approach possesses significantly potential in clinical diagnosis and prognosis evaluation of glycoprotein related diseases.