“…Recently, a number of DPPH• -based tests for the assessment of antioxidant activity have been developed. The evaluation of antioxidant capacity based on the amperometric reduction of DPPH• at the glassy carbon electrode was reported [14,15], TLC [16], HPLC techniques [17,18,19,20] and flow injection based methods for determination of scavenging capacity against DPPH• were also reported [21,22,23,24,25]. A DPPH• based optical sensor for screening of antioxidant activity was introduced by Steinberg et al [26].…”