A single-use, in vitro biosensor for the detection of T-Tau protein in phosphate-buffersaline (PBS) and undiluted human serum was designed, manufactured, and tested. Differentialpulse voltammetry (DPV) served as the transduction mechanism. This biosensor consisted of threeelectrodes: working, counter, and reference electrodes fabricated on a PET sheet. Both working andcounter electrodes were thin gold film, 10 nm in thickness. Laser ablation technique was used to definethe size and structure of the biosensor. The biosensor was produced using cost-effective roll-to-rollprocess. Self-assembled monolayers (SAM) of 3-mercaptopropionic acid (MPA) were employed tocovalently immobilize the anti-T-Tau (T-Tau antibody) on the gold working electrode. A carbodiimideconjugation approach using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC)and N-hydroxysuccinimide (NHS) cross-linked anti-T-Tau to the carboxylic groups on one endof the MPA. A T-Tau protein ladder with six isoforms was used in this study. The anti-T-Tauconcentration used was 500,000 pg/mL. The T-Tau protein concentration ranged from 1000 pg/mL to100,000 pg/mL. DPV measurements showed excellent responses, with a good calibration curve. Thus,a practical tool for simple detection of T-Tau protein, a biomarker of neuro-degenerative disorders,has been successfully developed. This tool could also be extended to detect other biomarkers forneuro-degenerative disorders, such as P-Tau protein and β-amyloid 42.
- 3-mercaptopropionic acid (MPA)
- Differential pulse voltammetry
- T-Tau protein detection
- [Fe(CN)] redox probe