Closed Bipolar Nanoelectrode Array for Ultra-Sensitive Detection of Alkaline Phosphatase and Two-Dimensional Imaging of Epidermal Growth Factor Receptors

ACS Sens. 2024 Jul 26;9(7):3754-3762. doi: 10.1021/acssensors.4c00918. Epub 2024 Jul 6.

Abstract

The combination of closed bipolar electrodes (cBPE) with electrochemiluminescence (ECL) imaging has demonstrated remarkable capabilities in the field of bioanalysis. Here, we established a cBPE-ECL platform for ultrasensitive detection of alkaline phosphatase (ALP) and two-dimensional imaging of epidermal growth factor receptor (EGFR). This cBPE-ECL system consists of a high-density gold nanowire array in anodic aluminum oxide (AAO) membrane as the cBPE coupled with ECL of highly luminescent cadmium selenide quantum dots (CdSe QDs) luminophores to achieve cathodic electro-optical conversion. When an enzyme-catalyzed amplification effect of ALP with 4-aminophenyl phosphate monosodium salt hydrate (p-APP) as the substrate and 4-aminophenol (p-AP) as the electroactive probe is introduced, a significant improvement of sensing sensitivity with a detection limit as low as 0.5 fM for ALP on the cBPE-ECL platform can be obtained. In addition, the cBPE-ECL sensing system can also be used to detect cancer cells with an impressive detection limit of 50 cells/mL by labeling ALP onto the EGFR protein on A431 human epidermal cancer cell membranes. Thus, two-dimensional (2D) imaging of the EGFR proteins on the cell surface can be achieved, demonstrating that the established cBPE-ECL sensing system is of high resolution for spatiotemporal cell imaging.

Keywords: anodic electrochemiluminescence; cell imaging; closed bipolar electrode; enzyme-catalyzed amplification; gold nanoelectrode array.

MeSH terms

  • Alkaline Phosphatase* / analysis
  • Alkaline Phosphatase* / chemistry
  • Alkaline Phosphatase* / metabolism
  • Biosensing Techniques / methods
  • Cadmium Compounds / chemistry
  • Cell Line, Tumor
  • Electrochemical Techniques / methods
  • Electrodes*
  • ErbB Receptors* / analysis
  • ErbB Receptors* / metabolism
  • Gold / chemistry
  • Humans
  • Limit of Detection
  • Luminescent Measurements / methods
  • Nanowires / chemistry
  • Quantum Dots / chemistry
  • Selenium Compounds / chemistry

Substances

  • ErbB Receptors
  • Alkaline Phosphatase
  • Cadmium Compounds
  • Selenium Compounds
  • cadmium selenide
  • Gold