Enhanced Immunosensor Using a Handheld pH Meter for the Point‐of‐Care, Sensitive Detection of Prostate Specific Antigen

Abstract

An enhanced handheld pH meter based immunosensor was proposed for point-of-care, quantitative determination of prostate specific antigen (PSA). Monoclonal antibody-functionalized magnetic beads (MB-Ab 1 ) were prepared to capture PSA in sample, and subsequently bond to polyclonal antibody-immobilized gold nanoparticles-polyamide-amine dendrite-lead ion (GO-PAMAM-Pb 2 + ) and dispersed in H 2 S solution. Based on negative Gibbs free energy of formation, PbS (solubility product constant K sp = 8.0 × 10 À 28 was formed by reaction of Pb 2 + and H 2 S. Hence, the pH of solution increased due to the H + appeared, and the resulting pH value was monitored by a handheld pH meter.

Diagnosis of disease relevant nucleic acid biomarkers with off-the-shelf devices

“…Owing to the significant impact of POC assays in clinical diagnosis, they have inspired many researchers to explore novel molecular transduction strategies on the basis of existing devices for public health monitoring. In addition to the repurposed devices mentioned above, there are many other inexpensive and widely accepted off-the-shelf devices adopted to detect nucleic acids such as pressure meters, 19,118,119 personal uric acid meters (PUAM), 20,120 pH meters [121][122][123] and thermometers. [124][125][126]…”

A nucleic acid-based magnetic potentiometric aptasensing platform for indirect detection of prostate-specific antigen with catalytic hairpin assembly

“…21 Potentiometric measurements are often carried out with a two-electrode system including working electrode and reference electrode without external excitement such as current and voltage. 22 23 To the best of our knowledge, a few reports were focused on the potentiometric measurement of cancer biomarkers. [24][25][26][27][28] One of major bottlenecks for potentiometric aptasensor is how to amplify the detectable signal.…”

“…21 Potentiometric measurements are often carried out with a two-electrode system including a working electrode and reference electrode without external excitement such as current and voltage. 22 Gao et al introduced a versatile approach to carry out potentiometric aptasensing of Escherichia coli by electrogenerated chemiluminescence. 23 To the best of our knowledge, a few reports were focused on the potentiometric measurement of cancer biomarkers.…”