Highly reliable label-free detection of urea/glucose and sensing mechanism using SiO2 and CdSe-ZnS nanoparticles in electrolyte-insulator-semiconductor structure

Pankaj Kumar, Siddheswar Maikap, Kanishk Singh, Subhodeep Chatterjee, Yi Yan Chen, Hsin Ming Cheng, Rajat Mahapatra, Jian Tai Qiu, Jer Ren Yang

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

A simple, label-free and cost effective sensor have been studied for reliable urea/glucose sensing, and common serum analyte detection comparable with market available urea "Assay Kit" is also performed by using SiO2 and CdSe-ZnS nanoparticles in electrolyte-insulator-semiconductor structure for the first time. Thermally grown SiO2 membrane has shown lower pH detection limit (0.081) and lowest drift rate (2.9 mV/hr) than those of the sputtering and E-beam deposited SiO2 membranes. The urea detection at physiological buffer pH 7.4 with sensitivity of ∼1.6 mV/mg.dl-1 at linear range of 6 to 36 mg/dl is shown. The pH detection limit is further reduced (0.074) by using chaperonin protein mediated CdSe-ZnS nanoparticles assembly over SiO2 surface owing to high pH sensitivity of 55 mV/pH. The sensing mechanism is due to the SiOx content decreased with increasing pH value. This suggests the lower H+ ions absorption on the sensing membrane surface, which is observed by X-ray photo-electron spectroscopy. The glucose concentration is detected by using the core-shell CdSe-ZnS nanoparticles through H2O2 sensing because of reduction/oxidation (redox) properties of Zn as well as Zn2+ ions generation. Due to the high catalytic activity for H2O2 sensitivity, low detection limit of 1 μM is obtained, which will help to detect glucose using this bio-chip in future.

Original languageEnglish
Pages (from-to)B580-B587
JournalJournal of the Electrochemical Society
Volume163
Issue number13
DOIs
Publication statusPublished - 2016
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

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