11 research outputs found
Spectrophotometric Determination of Phenols and Cyanides After Distillation from Natural Waters
Amperometric biosensors based on carbon paste electrodes chemically modified with redox-enzymes
Development of an Offline Noncompetitive Flow Immunoassay for the Determination of Interleukin-8 in Cell Samples
Automatic preconcentration of chlorophenols and gas chromatographic determination with electron capture detection
Integrated biodetection in a nanofluidic device
The sensing of enzymatic processes in volumes at or below the scale of single cells is challenging but highly desirable in the study of biochemical processes. Here we demonstrate a nanofluidic device that combines an enzymatic recognition element and electrochemical signal transduction within a six-femtoliter volume. Our approach is based on localized immobilization of the enzyme tyrosinase in a microfabricated nanogap electrochemical transducer. The enzymatic reaction product quinone is localized in the confined space of a nanochannel in which efficient redox cycling also takes place. Thus, the sensor allows the sensitive detection of minute amounts of product molecules generated by the enzyme in real time. This method is ideally suited for the study of ultra-small-volume systems such as the contents of individual biological cells or organelles