Biosensing based on surface-enhanced raman spectroscopy

In view of basic science, to understand biological systems increasingly depends on our ability to dynamically and quantitatively measure the molecular processes with high sensitivity, speed, exibility, multiplexity, throughput, and reproducibility, usually within the context of a complex biological and chemical mixture of a tiny amount. A living cell responds to its changing environment both inside and outside itself in such a dynamic way that hundreds and thousands of signaling proteins, enzymes, siRNA, DNA, mRNA, and transcription and translation factors are constantly modied or synthesized, transferred from one organelle to another, and perform appropriate cell functions in macromolecule complexes, behaving like an army of molecular machines working in perfect synchronicity and harmony. These biomolecular complexes are not only heterogeneously distributed, recombined, modied, and reassembled continuously, but perpetually changed over time with the change of surrounding microenvironments [1]. To quantitatively follow the biochemical reactions within multimolecule complexes, it is vital for the general goal of intimately following the molecular machines in cell signaling, growth, differentiation, apoptosis, cell developmental processes, and relevant diseases. In the biotechnology industry, combinatorial methods are increasingly applied to synthesize new biocatalysts or drugs, demanding the simultaneous analysis of thousands of pathogens, mutants, drug target enzymes, or therapeutic drugs themselves. Furthermore, in personalized medicine, as dictated by economic reasons, the mass application of screening and diagnostic tools have to be fast, convenient, and low cost, requiring the miniaturization, parallelization, integration, as well as automation of biosensing devices.