Fluorescence assay for glycan expression on living cancer cells based on competitive strategy coupled with dual-functionalized nanobiocomposites

Abstract

Cell surface glycans are a class of sophisticated biomolecules related to cancer development and progression, and their analysis is of great significance for early cancer diagnosis and treatment. In this paper, we proposed a fluorescence assay to evaluate glycan expression on living cancer cells based on a competitive strategy coupled with dual-functionalized nanobiocomposites. The competitive assay was conducted between living cancer cells and thiomannosyl derivatives using concanavalin A (Con A)-modified electrode as the interaction platform. To impart fluorescence signaling ability to competitive derivatives, quantum dots (QDs) were anchored on BSA-protected Au nanoparticles, and thiomannosyl derivatives were further immobilized on the nanoparticle surface through Au-S binding. Due to the spacing between QDs and Au nanoparticles by BSA, the {QDs-Au-BSA-mannose} nanobiocomposites maintained the fluorescence of QDs and showed binding ability with the Con A-modified electrode. Au nanorods (AuNRs)-modified electrode was used as an effective substrate to immobilize Con A. This assay was successfully applied to the analysis of two cancer cells lines (A549 and QGY-7701). The method is simple and shows promise for the study of glycan expression on living cancer cells.

A recyclable chitosan-based QCM biosensor for sensitive and selective detection of breast cancer cells in real time

“…The most recent efforts in cancer cell detection have focused on biosensors with good sensitivity and selectivity, as well as rapid and easy operation. Various biosensors using different transducers have been reported as effective in detecting and identifying cancer cells, including those based on electrochemical measurements, [7][8][9][10][11][12] uorescence measurements, 13,14 single nanotube eld effect transistor arrays 15 and microuidic devices. 16 Although many of them have been applied at the laboratory research level, they are difficult to regenerate or suffer from time-consuming steps for labeling or off-line analysis.…”

Fluorescence based fiber optic and planar waveguide biosensors. A review

“…Concanavalin A (ConA) [175] is the most widely used lectin in optical sensors. Several sensing schemes have been applied in the development of optical biosensors based on ConA but competitive and sandwich assays are the most used [176,177]. Besides, the majority are associated to the use of advanced fluorescence techniques such as FRET and fluorescent nanomaterials [178].…”

Recent Progress in Lectin-Based Biosensors

“…The sensor showed linear calibration graphs for the logarithmic concentrations ranging from 1.7 × 10 3 to 1.5 × 10 8 cells/mL for 95-D with a lower detection limit of 580 cells/mL and from 2.5 × 10 to 1.0 × 10 6 cells/mL for H1299 with the detection limit of 12 cells/mL. In a similar strategy using Au nanoparticle/quantum dot composites, A549 lung cancer cells and QGY-7701 liver cancer cells in the concentrations ranging from 10 to 10 7 cells/mL and from 10 4 to 10 7 cells/mL, respectively, were detected based on the fluorescence emission of the quantum dots [123]. Other nanomaterials useful for enhancing the response of lectin-based cytosensors include nanocomposites comprising Ru(bpy) 3 2+ -doped Au/silica nanoparticles [124], HRP/aptamer-modified Au nanoparticles [125], protein-modified silver nanoflowers [126], and GOx-modified Au nanoparticles [127].…”