Plenary Speech from UPM
Title:
Dual Amperometric Aptasensor for Simultaneous Detection of CFP10 and MPT64 Tuberculosis Antigens
Speaker:
Prof. Dr. Nor Azah Yusof
Institute of Nanoscience and Nanotechnology (ION2), Universiti Putra Malaysia (UPM)
On 12th DEC. 11:05am - 11:50am (JPN) / 10:05am - 10:50am (MYT)
Abstract:
In managing tuberculosis (TB), prompt and accurate diagnosis is of the utmost significance for life-saving and transmission cessation. Despite being time-consuming and having a low sensitivity, traditional smear microscopy and culture procedures remain the mainstay of TB antigen detection modality. This work highlights the fabrication of the first amperometric dual aptasensor for the simultaneous detection of Mycobacterium tuberculosis CFP10 and MPT64-secreted antigens to facilitate better TB diagnosis. The proposed sensor utilized the sandwich assay format measured by chronoamperometry via an electrocatalytic reaction between peroxidase-conjugated antibodies, hydrogen peroxide, and hydroquinone. Aptamers were immobilized via carbodiimide covalent chemistry over the disposable screen-printed carbon electrodes modified with a diazonium salt. The successful deposition of the diazonium layer was verified with x-ray photoelectron spectroscopy, Fourier-transform infrared, contact angle, and electrochemical analysis. Exceptional analytical performances were obtained on both working sensors with the detection limit of 1.62 (CFP10) ng mL–1 and 1.82 (MPT64) ng mL–1 with no significant reaction when incubated with other non-target reagents. In the clinical study, the MPT64 working sensor was the least sensitive (91.7%), followed by the CFP10 working electrode (95.8%). A combined CFP10–MPT64 detection achieved a perfect score for TB diagnosis with an overall 100% diagnostic sensitivity and specificity achieved for dual aptasensor when evaluated on 24 TB (+) and 13 TB (–) sputum samples. The developed dual amperometric aptasensor is a potentially sensitive, specific, and easy-to-apply assay for TB. Therefore, it would be a promising alternative to conventional methods