Gold Nanorod-Based Bio-Barcode Sensor Array for Enzymatic Detection in Biomedical Applications

Early diagnosis of disease onset requires sensor systems that detect multiple disease-related processes within the body. However, major obstacles must be surmounted for in vivo sensor use, including size, biocompatibility, sensitivity, and selectivity. As an initial study, here we fabricated a multidimensional gold nanorod (GNR)-based bio-barcode sensing array for sensitive and selective detection of biological events. The sensor comprises an array of gold nanocavities and GNRs that are bound to the array as well as to fluorescein via bio-barcode peptides. Exposure of the sensor to peptide-specific enzymes as inputs led to bio-barcode cleavage, which produced distinct optical-based output, that is, changes in fluorescence lifetime and surface plasmon resonance. The sensor showed sensitivity and selectivity to each biomarker input alone, as well as simultaneous distinguishable responses to their combination. By performing AND, OR, and XOR operations at the sensing system level, the biological events can be simply detected. This GNR-based bio-barcode sensor, incorporating plasmonic and fluorescent-enhancing nanotechnologies, is versatile and adaptable and thus has the potential to enable detection of a wide range of biomarkers to provide complex and advanced detection capabilities that have not been previously possible.