Determination of glucose in human stomach cancer cell extracts and single cells by capillary electrophoresis with a micro-biosensor

- Glucose in single human stomach cancer cells was first determined by CE-ECD.
- CNTs and Pd nanoparticles modified micro-biosensor with CE was constructed.
- BSA and GA provided biocompatible environment and immobilized GOx firmly in the film.
- The concentration of glucose was determined with high sensitivity and stability.

Bioactive species in cells can provide information about signal transduction, cell function, and the effects of disease treatment. In this article, a novel micro-biosensor was fabricated to detect glucose in individual human stomach cancer cells (MGC80-3 cells) with capillary electrophoresis (CE). We fabricated the micro-biosensors by immobilizing a single-walled carbon nanotube-glucose oxidase (GOx)-glutaraldehyde (GA) bio-composite at the palladium nanoparticle (PdNPs) modified Pt electrode. The linear concentration of glucose ranged from 2.0 μM to 1.0 mM, with a detection limit of 0.5 μM. Using this method, the mean amount of glucose in MGC80-3 cell extracts and in single cells was 20.0 fmol and 20 ± 6 fmol (n = 10), respectively. The micro-biosensor exhibited high sensitivity, stability, and a long operating life, which are likely due to the biocompatible environment provided by BSA and GA, and the adsorption and faster electron transfer of SWNTs and PdNPs to GOx.