Ultrasensitive Photoelectrochemical Biosensing of Cell Surface N-Glycan Expression Based on the Enhancement of Nanogold-Assembled Mesoporous Silica Amplified by Graphene Quantum Dots and Hybridization Chain Reaction

Abstract

An ultrasensitive photoelectrochemical (PEC) biosensor for N-glycan expression based on the enhancement of nanogold-assembled mesoporous silica nanoparticles (GMSNs) was fabricated, which also combined with multibranched hybridization chain reaction (mHCR) and graphene quantum dots (GQDs). In this work, the localized surface plasmon resonance, mHCR and GQDs-induced signal amplification strategies were integrated exquisitely and applied sufficiently. In the fabrication, after porous ZnO spheres immobilized on the Au nanorod-modified paper working electrode were sensitized by CdTe QDs, the GMSNs were assembled on the CdTe QDs. Then the photocurrent efficiency was improved by the sensitization of the CdTe QDs and the localized surface plasmon resonance of GMSNs. Successively, the products of mHCR with multiple biotins for multiple horseradish peroxidase binding and multiple branched arms for capturing the target cells were attached on the as-prepared electrode. The chemiluminescent (CL) emission with the aid of horseradish peroxidase served as an inner light source to excite photoactive materials for simplifying the instrument. Furthermore, the aptamer could capture the cancer cells by its highly efficient cell recognition ability, which avoided the conventional routing cell counting procedures. Meanwhile, the GQDs served as the signal amplication strategy, which was exerted in the process of N-glycan evaluation because the competitive absorption of exciting light and consumption of HO served as the electron donor of the PEC system and the oxidant of the luminol-based CL system. This judiciously engineered biosensor offered a promising platform for the exploration of N-glycan-based physiological processes.

Applications of Graphene Quantum Dots in Biomedical Sensors

“…In 2017, Ge at al. designed a PEC biosensor for expressing N-glycan, depending on the properties offered by nanogold-conjoined mesoporous silicon NPs (GMSNs) fused with localized SPR and GQDs [356]. In the development of a desired sensor, porous zinc oxide (ZnO) spheres were integrated on the Au nanorod-functionalized paper WE and were modified with the assistance of CdTe QDs.…”

Metal Species–Encapsulated Mesoporous Silica Nanoparticles: Current Advancements and Latest Breakthroughs

“…In addition, various combinations of metals have also been encapsulated in the mesoporous materials, including bimetallic systems, metal‐immobilized core (metal)‐mesoporous silica shell systems21d/metal‐modified MSNs and others, such as alkali metal ion‐modified MSNs 27a. These hybrid materials have gained potential interests in various fields such as adsorption,35,37,42c catalysis,14d,17,34,41d,54 drug delivery,21a,27c,42e bioimaging,42f photoluminescence,51b biosensing, gas sensing,53a and radioactive metal sorption 42a…”

“…The exceptional topology of surfactant‐templated MSNs makes them unique with desirable properties that can be obtained by controlling the preparation conditions, such as the reaction temperature, pH value, stirring speed, and type of silica source, as well as surfactant, among others 4j,m,n,5. These advantages make the MSNs as versatile materials and ideal choice for catalysis, adsorption, optical devices,4j polymeric fillers, and diverse biomedical applications including bio‐imaging,4r,t,u,9 biocatalysts, biosensing, tissue engineering,4f and drug/gene delivery accounting for targeted and controlled release systems 3d,4i,o‐t,v,12…”

Affinity-Based Detection of Biomolecules Using Photo-Electrochemical Readout

“…This biosensor exhibited an LOD of 3 cells mL −1 with a linear range of 1 × 10 3 -5 × 10 7 cells mL −1 (Figure 7A). A paper-based cytosensor was reported for detecting breast cancer cells (MCF-7) constructed from ZnO spheres immobilized on Au nanorod-modified paper and sensitized with CdTe QDs and nanogold-assembled mesoporous silica nanoparticles (GMSNs) at their surface to create the photoactive portion of the biosensor (Ge et al, 2017). Multiple horseradish peroxidase (HRP) molecules and branched capture sites were then immobilized onto the GMSNs using double stranded DNA (Figure 7C).…”