Département de chimie moléculaire

A simple square wave voltammetric method for trypsin activity detn., based on 1,2-benzoquinone electrochem. redn. on gelatin coated screen printed electrodes requiring small (30 $μ$L) sample vol. was developed. The proteolytic digestion of the gelatin film facilitated the transport of the electroactive specie to the electrode surface and resulted in redn. peak current increase. Current response as a function of trypsin concn. within 10 min of incubation time was evaluated in the range of 0.1-1000 $μ$g mL-1 trypsin corresponding to enzyme activity in the range from 0.75 U mL-1 to 7500 U mL-1, resp. The limit of detection was detd. to be as low as 0.01 $μ$g mL-1 (0.075 U mL-1) trypsin after 140 min incubation time. The optimal hydrogel permeability defined by the concn. and the vol. of the deposited gelatin soln. (6{%} and 8 $μ$L, resp.) was established performing preliminary expts. using a gelatin modified glassy carbon electrode of conventional type and applying factorial design approach. The method allows a rapid trypsin activity detn. in the normal and acute pancreatitis range, taking advantage of the low cost and disposability of the mass produced screen printed electrodes, suitable for point-of-care testing. [on SciFinder(R)]