Ascorbic acid imprinted polymer-modified graphite electrode: A diagnostic sensor for hypovitaminosis C at ultra trace ascorbic acid level

作者：Prasad Bhim Bali^*; Kumar Deepak; Madhuri Rashmi; Tiwari Mahavir Prasad

来源：Sensors and Actuators B: Chemical , 2011, 160(1): 418-427.

DOI：10.1016/j.snb.2011.08.003

• Ascorbic acid
• Differential pulse anodic striping voltammetry
• Molecularly imprinted polymer
• Sol-gel
• " Grafting-to" approach

A new kind of molecularly imprinted polymer-modified graphite electrode was fabricated by "grafting-to" approach, incorporating sol-gel technique, for the detection of acute deficiency in serum ascorbic acid level (SAAL), manifesting hypovitaminosis C. The modified electrode exhibited ascorbic acid (AA) oxidation at less positive potential (0.0 V) than the earlier reported methods, resulting in a limit of detection as low as 6.13 ng mL(-1) (RSD = 1.2%, S/N = 3). The diffusion coefficient (1.096 x 10(-5) cm(2) s(-1)), rate constant (7.308 s(-1)). and Gibb's free energy change (-12.59 kJ mol(-1)) due to analyte adsorption, were also calculated to explore the kinetics of AA oxidation. The proposed sensor was found to enhance sensitivity substantially so as to detect ultra trace level of AA in the presence of other biologically important compounds (dopamine, uric acid, etc.), without any cross interference and matrix complications from biological fluids and pharmaceutical samples.

• 出版日期2011-12-15