Diagnosis of Diabetes in a Diabetic Patient's Urine and Blood Using a Combination Electrode with a Ubiquitous Handheld Analyzer

Glucose assay was conducted on untreated diabetic patient's urine and blood using a combination electrode (CE) whose sensor was interfaced with a newly constructed handheld voltammetry. The CE was prepared using the common graphite pencil as a working electrode, handmade reference electrode, and platinum counter electrode, which were combined into one electrode system. The CE was optimized through cyclic and stripping voltammetry. Analytical working range was attained at 30.0-300.0 ugL-1 and at 100-800 ugL-1, under different conditions. The relative standard deviation of 0.5 mg/L that was observed at the optimum condition was 0.31% (n=15). The detection limit (S/N) was attained at 13.7 ugL-1 (7.6x10-8 M). The system that was developed in this study is compact and can be useful in ubiquitous, selfdiagnosis, and fast assays.