A urinary microalbumin test is used to detect early signs of kidney damage in people who have a risk of chronic kidney disease, such as those with diabetes or hypertension. In this study, we developed a screen-printed carbon electrode-based immunosensor for the detection of microalbumin in urine. Anti-human albumin antibodies were immobilized on the screen-printed sensor surface by the covalent immobilization method. Cyclic voltammetry (CV) and scanning electron microscopy with an energy dispersive spectroscopical (SEM-EDS) analysis demonstrated that the modification process was well performed. Chronoamperometric (CA) electrochemical measurement technique was employed for the quantitative detection of albumin. The electrochemical measurements performed with some possible interfering compounds normally present in urine (ascorbic acid, uric acid, glucose and creatinine samples) demonstrated a high specificity and selectivity of this immunosensor in albumin detection. Under optimum conditions, the immunosensor can detect urinary albumin in a wide linear range from 10 µg/ml to 300 µg/ml with a detection limit of 9.7 µg/ml. The excellent performance of this immunosensor was confirmed by analyzing microalbumin in urine samples; the results were in good agreement with those obtained by the standard immunoturbidimetric method. The biosensor proposed herein is easy to prepare and can be used for low-cost, rapid, and sensitive screening of microalbuminuria. This approach provides a promising platform for developing clinical point-of-care diagnostic applications.
Keywords: Chronoamperometry; Immunosensor; Microalbuminuria; Screen-printed carbon electrode.
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