Background: Metformin (Mf) (N,N’-Dimethylbiguanide) is used as the first-line medication for treating diabetes mellitus type II. It is also considered as a “gold standard” treatment for various diseases like hyperglycemia, insulin resistance, infertility, cardiovascular disease, renal dysfunction, polycystic ovary syndrome, obesity, cancer and ageing. Majority of the methods available for quantitative analysis of Mf are expensive, time-consuming, require sample pre-treatment and skilled persons to operate. Electrochemical sensors overcome these drawbacks, as these are fast, simple, cost-effective, specific and highly sensitive.
Methods: The updated literature and online papers related to Mf sensors as well as other methods were collected, analyzed and reviewed to provide the comprehensive information about the Mf sensing. The review was critically evaluated and concluded, emphasizing on future perspectives for Mf sensors.
Results: The review presented the basic principles, merits and demerits of various conventional techniques for metformin determination in pharmaceuticals and biological samples with special emphasis on electrochemical sensors. Further, the review highlighted the updated summary of the recent advances in terms of the latest nanomaterials modified electrodes used for fabrication of Mf sensors.
Conclusion: Metformin sensors worked optimally within 0.6 to 120s, between pH, 7 to 12 and temperature 30°C to 40°C and in the concentration range, 0.015 nmol/L to 6500 nmol/L, with detection limits between 0.33nmol/L to 0.45µM/L. These sensors measured metformin level in the pharmaceutical preparations, sera and urine samples and reused over a period of 21 to 120 days. The technical challenges and future perspective for further improvement in Mf sensors and their miniaturization are also discussed.
Keywords: Metformin, antidiabetic drug, metformin sensor, serum, pharmaceutical preparation of metformin, nanomaterials.