Electrochemical detection of cardiac troponin I using a microchip with the surface-functionalized poly(dimethylsiloxane) channel.

A sensitive and rapid electrochemical microchip fabricated by assembling a surface-functionalized poly(dimethylsiloxane) (PDMS) microchannel with an interdigitated array (IDA) gold electrode was developed for the detection of human cardiac troponin I (cTnI) in the early diagnosis of acute myocardial infarction. Anti-cTnI was immobilized onto the internal surface of the PDMS channel on which protein G layer had been generated by silanization. To reduce electrode fouling, a PDMS channel was assembled with an IDA chip after surface treatment. The detection experiments were performed with successive injection of cTnI, alkaline phosphatase (AP)-labeled anti-cTnI, and p-aminophenylphosphate. Then, cyclic voltammograms were obtained by the oxidation peak current proportionally to the concentration of enzymatic product, p-aminophenol. The optimal packing density of anti-cTnI on the surface of the PDMS channel was determined at the anti-cTnI concentration of 30 microg/ml for the highest electrochemical signal. These demonstrate that the proper orientation and best packing density of antibody as well as no electrode fouling contributed to the low detection limit (148 pg/ml) of cTnI within 8 min.

Role of echocardiography in sinus venosus atrial septal defect combined with systemic and pulmonary vascular disease.

We present a case of persistent left superior vena cava, anomalous right pulmonary venous connection to the right-sided superior vena cava and sinus venosus atrial septal defect detected by computed tomography (CT) pulmonary angiography and echocardiography. These defects were surgically corrected using a double-patch technique. In fact, CT can provide anatomical information about a complex anomaly in the systemic and pulmonary vasculatures. Though modern imaging techniques are useful for detecting complex cardiovascular disease, careful echocardiographic examination should be performed to diagnose complex cardiac anomalies.