Point-of-care impedimetric aptasensor to detect the luteinizing hormone

• Published in: Mikrochimica acta (1966) Vol. 191; no. 2; p. 115
• Main Authors: Kumar, Pankaj, Anitha, Arumugam, Das, Ankita, Deepalakshmi, Govindarajan, Suman, Pankaj
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.02.2024; Springer Nature B.V
• Subjects: Ambient temperature; Analytical Chemistry; Animals; Antibodies; Aptamers, Nucleotide - chemistry; Biomarkers; Biosensing Techniques - methods; Cattle; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Electrochemical impedance spectroscopy; Electrochemical Techniques - methods; Frequency ranges; Luteinizing Hormone; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Ovulation; Point-of-Care Systems; Radioimmunoassay; Room temperature; Smartphones; Luteinizing hormone; Screen-printed gold electrode; Ovulation prediction; Aptasensor; Electrochemical impedance spectroscopy
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-024-06191-w

Luteinizing hormone (LH) is a useful biomarker for identifying ovulation events in the cows to predict the time of ovulation to achieve a high success rate of conception following artificial insemination. Although antibody-based radioimmunoassay and enzyme-linked immunosorbent assay are being used for LH measurement, these techniques are expensive, time-consuming, and require expertise and sophisticated laboratory facilities. So, there is a need for a field-applicable, affordable, easy-to-use method for LH detection. For developing such a specific, quantitative, and inexpensive system, an aptamer-based smartphone-enabled aptasensor has been investigated. The aptamer was used instead of the antibody as a biorecognition element due to its comparative stability at ambient temperature, ease of synthesis, and cost-effectiveness. Electrochemical impedance spectroscopy has been used to obtain label-free detection of LH within 20 min in ~ 20 μL sample volume. The screen-printed gold electrode is compatible with a smartphone-enabled miniaturized device (Sensit Smart; Palmsens BV, The Netherlands) and was fabricated with the aptamer to detect LH in biological fluids (limit of detection 0.80 and 0.61 ng/mL in buffer and undiluted/unprocessed serum, respectively, with the dynamic range of detection of 0.01 to 50 ng/mL). All the data were obtained in the 10 kHz to 0.10 Hz frequency range at a bias potential of 0.30 V with an alternating potential of 10 mV. The clinical relevance of the sensor was evaluated in 10 serum samples collected from dairy animals which established a high correlation with standard LH-ELISA ( κ > 0.87). The aptasensor can be stored at room temperature for 30 days without any significant loss in electrochemical sensing ability. Graphical Abstract