Single-Use Disposable Electrochemical Label-Free Immunosensor for Detection of Glycated Hemoglobin (HbA1c) Using Differential Pulse Voltammetry (DPV)

Sensors (Basel). 2016 Jul 1;16(7):1024. doi: 10.3390/s16071024.

Abstract

A single-use disposable in vitro electrochemical immunosensor for the detection of HbA1c in undiluted human serum using differential pulse voltammetry (DPV) was developed. A three-electrode configuration electrochemical biosensor consisted of 10-nm-thin gold film working and counter electrodes and a thick-film printed Ag/AgCl reference electrode was fabricated on a polyethylene terephthalate (PET) substrate. Micro-fabrication techniques including sputtering vapor deposition and thick-film printing were used to fabricate the biosensor. This was a roll-to-roll cost-effective manufacturing process making the single-use disposable in vitro HbA1c biosensor a reality. Self-assembled monolayers of 3-Mercaptopropionic acid (MPA) were employed to covalently immobilize anti-HbA1c on the surface of gold electrodes. Electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) confirmed the excellent coverage of MPA-SAM and the upward orientation of carboxylic groups. The hindering effect of HbA1c on the ferricyanide/ferrocyanide electron transfer reaction was exploited as the HbA1c detection mechanism. The biosensor showed a linear range of 7.5-20 µg/mL of HbA1c in 0.1 M PBS. Using undiluted human serum as the test medium, the biosensor presented an excellent linear behavior (R² = 0.999) in the range of 0.1-0.25 mg/mL of HbA1c. The potential application of this biosensor for in vitro measurement of HbA1c for diabetic management was demonstrated.

Keywords: 3-MPA; HbA1c; differential pulse voltammetry; immunosensor.

MeSH terms

  • 3-Mercaptopropionic Acid / chemistry
  • Animals
  • Biosensing Techniques / instrumentation*
  • Cattle
  • Dielectric Spectroscopy
  • Electrochemical Techniques / instrumentation*
  • Glycated Hemoglobin / analysis*
  • Gold / chemistry
  • Humans
  • Photoelectron Spectroscopy
  • Serum / metabolism
  • Signal Processing, Computer-Assisted
  • Staining and Labeling*

Substances

  • Glycated Hemoglobin A
  • Gold
  • 3-Mercaptopropionic Acid