English August 19, 2025

Dry-printed carbon nanotube film based electrochemical immunosensor for total testosterone detection

Joon et al. (2025): https://doi.org/10.1016/j.biosx.2025.100660

Highlights

Efficiency of Dry printed carbon nanotube film for electrochemical sensing.
Pristine carbon nanotube film for detection of testosterone.
Electrochemical-based testosterone biosensor for human serum samples.
Immunosensor for testosterone, matching commercial ELISA kit performance.
Short-term room temperature storage of testosterone sensors.

Abstract

Testosterone (TST), a critical hormone for male health, requires precise monitoring due to the significant adverse effects of both deficiency and excess, including reproductive dysfunction, mood alterations, and metabolic imbalances. This study reports a novel electrochemical biosensor designed for rapid and sensitive point-of-care (POC) detection of total TST in serum samples.

The sensing platform utilizes a cost-effective, roll-to-roll processed carbon nanotube (CNT) film as a scaffold. To create the biorecognition layer, bovine serum albumin-testosterone conjugate (BSA TST) was uniformly immobilized into the CNT film using an automated liquid dispensing system, enabling high-throughput and reproducible sensor fabrication. The biosensor employs a competitive immunoassay principle, where TST in the sample competes with immobilized BSA TST for the binding sites of antibody against TST horse-radish peroxidase conjugate (AbHRP). Amperometry at −0.2 V vs. Ag/AgCl ink was used to monitor affinity reaction upon addition of H₂O₂ with 3,3′,5,5′-Tetramethylbenzidine (TMB) redox mediator yielding a dynamic range of 82–1080 ng/dL. Limit of detection (LOD) and limit of quantification (LOQ) of 12.7 and 82 ng/dL were achieved respectively.

Validation in spiked human serum demonstrated excellent performance, with quantifiable results aligning well with the established physiological range of TST in healthy males (186–1180 ng/dL), highlighting the potential of this biosensor for clinical applications.

Main conclusions

Innovative Biosensor: Electrochemical immunosensor was developed for TST using Canatu novel dry-printed carbon nanotube electrodes and a competitive immunoassay.
High Performance: The biosensor demonstrated excellent analytical performance, including strong stability, rapid detection, and good reproducibility for measuring TST in human serum.
Clinical Relevance: The biosensor provides accurate and cost-effective total TST quantification comparable to traditional, more time-consuming ELISA methods. Its potential applications include clinical diagnostics, sports, and general wellness.
Future Direction: Future work will focus on validating the developed biosensor with fresh human serum samples from diverse patients, expanding its application to include clinically relevant ranges for women and children.