According to the World Health Organization, cardiovascular disease is the most common cause of death in the world. In the US, over 115 million people visit the emergency department (ED), 5 million of which may have acute coronary syndrome (ACS). Cardiac biomarkers can provide early identification and diagnosis of ACS, and can provide information on the prognosis of the patient by assessing the risk of death. In addition, the biomarkers can serve as criteria for admission, indicate possibility of re-infarction, or eliminate ACS as a diagnosis altogether. We propose a SERSbased multi-marker approach towards a point-of-care diagnostic system for ACS. Using a nanofluidic device consisting of a microchannel leading into a nanochannel, we formed SERS active sites by mechanically aggregating gold particles (60 nm) at the entrance to the nanochannel (40 nmx1 ìm). The induced capillary flow produces a high density of aggregated nanoparticles at this precise region, creating areas with enhancedelectromagnetic fields within the aggregates, shifting the plasmon resonance to the near infrared region, in resonance with incident laser wavelength. With this robust sensing platform, we were able to obtain qualitative information of brain natriuretic peptide (biomarker of ventricular dysfunction or pulmonary stress), troponin I (biomarker of myocardial necrosis), and C-reactive protein (biomarker of inflammation potentially caused by atherosclerosis). © 2009 SPIE.
- Cardiac BiomarkerSurface EnhancedSersNanochannelNanofluidic DeviceRaman SpectroscopyCOLLOIDAL GOLDPoint-of-care Diagnostics