NG-Hydroxy-L-arginine, NOHA, is a suspected biomarker in rare and aggressive cases of breast cancer (1). NOHA was found to have antiproliferative and apoptotic actions on arginase expressing human breast cancer cells (1). The most promising approach in the treatment of cancer is to undergo rapid treatment options as a result from early diagnosis of cancer (2). Detecting the onset of cancer in a fast, cost efficient, and at optimal range is essential for greater treatment options. Electrochemical detection is a proven, established, cost-effective method to successfully detect low levels of analyte concentrations. Ideally one wants to detect NOHA on a nanomolar scale, because NOHA is present in serum in low concentrations. The goal of initial experiments where to optimize a NOHA sensor at a bare glassy carbon electrode. By comparing the detection methods of cyclic voltammetry to differential pulse voltammetry, we evaluated the best detection techniques for future experiments in NOHA detection. Each method will be evaluated on several criteria. First, we will monitor the oxidation peak for any voltage shifts as a function of concentration. Our experience indicates that a shift in the peak voltage would make the creation of a precise calibration curve difficult. Next, we will observe the relationship between the current response and concentration. The most accurate calibration curves are linear, and we will report on the linearity of NOHA’s oxidation current response versus concentration. In the future attachment of copper polyaniline film will be used in enhance the surface of the electrode using the best electrochemical detection method.
(1) R. Singh, S. Pervin, a Karimi, S. Cederbaum, and G. Chaudhuri, “Arginase activity in human breast cancer cell lines: N(omega)-hydroxy-L-arginine selectively inhibits cell proliferation and induces apoptosis in MDA-MB-468 cells,” Cancer Res., vol. 60, no. 12, pp. 3305–3312, (2000)
(2) Zhen Zhang, Robert C. Bast, Jr., Yinhua Yu, Jinong Li, Lori J. Sokoll, Alex J. Rai, Jason M. Rosenzweig, Bonnie Cameron, Young Y. Wang, Xiao-Ying Meng, Andrew Berchuck, Carolien van Haaften-Day, and Neville F. Hacker, Henk W. A. de Bruijn, Ate G. J. van der Zee, Ian J. Jacobs, Eric T. Fung, and D. W. Chan, “Three Biomarkers Identified from Serum Proteomic Analysis for the Detection of Early Stage Ovarian Cancer,” Cancer Res., vol. 64, pp. 5882–5890, (2004)