posted on 2024-03-15, 23:29authored byParisa Dehghani, Vaithinathan Karthikeyan, Ataollah Tajabadi, Dani S. Assi, Anthony Catchpole, John Wadsworth, Hing Y. Leung, Vellaisamy A. L. Roy
With the global escalation of concerns surrounding prostate
cancer
(PCa) diagnosis, reliance on the serologic prostate-specific antigen
(PSA) test remains the primary approach. However, the imperative for
early PCa diagnosis necessitates more effective, accurate, and rapid
diagnostic point-of-care (POC) devices to enhance the result reliability
and minimize disease-related complications. Among POC approaches,
electrochemical biosensors, known for their amenability and miniaturization
capabilities, have emerged as promising candidates. In this study,
we developed an impedimetric sensing platform to detect urinary zinc
(UZn) in both artificial and clinical urine samples. Our approach
lies in integrating label-free impedimetric sensing and the introduction
of porosity through surface modification techniques. Leveraging a
cellulose acetate/reduced graphene oxide composite, our sensor’s
recognition layer is engineered to exhibit enhanced porosity, critical
for improving the sensitivity, capture, and interaction with UZn.
The sensitivity is further amplified by incorporating zincon as an
external dopant, establishing highly effective recognition sites.
Our sensor demonstrates a limit of detection of 7.33 ng/mL in the
0.1–1000 ng/mL dynamic range, which aligns with the reference
benchmark samples from clinical biochemistry. Our sensor results are
comparable with the results of inductively coupled plasma mass spectrometry
(ICP-MS) where a notable correlation of 0.991 is achieved. To validate
our sensor in a real-life scenario, tests were performed on human
urine samples from patients being investigated for prostate cancer.
Testing clinical urine samples using our sensing platform and ICP-MS
produced highly comparable results. A linear correlation with R2 = 0.964 with no significant difference between
two groups (p-value = 0.936) was found, thus confirming
the reliability of our sensing platform.