A Graphene-Based Enzymatic Biosensor Using a Common-Gate Field-Effect Transistor for L-Lactic Acid Detection in Blood Plasma Samples

• Published in: Sensors (Basel, Switzerland) Vol. 21; no. 5; p. 1852
• Main Authors: Schuck, Ariadna, Kim, Hyo Eun, Moreira, Júlia Konzen, Lora, Priscila Schmidt, Kim, Yong-Sang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06-03-2021; MDPI
• Subjects: Ascorbic acid; Biosensing Techniques; biosensor; Biosensors; Blood plasma; Buffer solutions; Chemical reactions; Chemical vapor deposition; Chitosan; Dehydrogenases; Electrodes; Enzymes; Field effect transistors; field-effect transistor; Flexible components; Glass substrates; Graphene; Graphite; Guarantees; Hemorrhage; Humans; Ischemia; L-Lactate Dehydrogenase; lactate; Lactate dehydrogenase; Lactic Acid; Measurement techniques; Metabolism; Organic chemistry; Plasma; Respiratory failure; Room temperature; Selectivity; Semiconductor devices; Sensors; Sepsis; Stability; Transistors; Uric acid; United States > US; lactate dehydrogenase; biosensor; field-effect transistor; lactate; graphene
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s21051852

Lactate is an important organic molecule that is produced in excess during anaerobic metabolism when oxygen is absent in the human organism. The concentration of this substance in the body can be related to several medical conditions, such as hemorrhage, respiratory failure, and ischemia. Herein, we describe a graphene-based lactate biosensor to detect the concentrations of L-lactic acid in different fluids (buffer solution and plasma). The active surface (graphene) of the device was functionalized with lactate dehydrogenase enzyme using different substances (Nafion, chitosan, and glutaraldehyde) to guarantee stability and increase selectivity. The devices presented linear responses for the concentration ranges tested in the different fluids. An interference study was performed using ascorbic acid, uric acid, and glucose, and there was a minimum variation in the Dirac point voltage during detection of lactate in any of the samples. The stability of the devices was verified at up to 50 days while kept in a dry box at room temperature, and device operation was stable until 12 days. This study demonstrated graphene performance to monitor L-lactic acid production in human samples, indicating that this material can be implemented in more simple and low-cost devices, such as flexible sensors, for point-of-care applications.