Two-dimensional surface plasmon resonance imaging system for cellular analysis

Abstract

Optical biosensors based on surface plasmon resonance (SPR) phenomenon have received a great deal of attention in cellular analysis applications. Sensitive and high-resolution SPR imaging (SPRi) platforms are very useful for real-time monitoring and measurement of individual cell responses to various exogenous substances. In cellular analysis, mainstream SPR-based sensors have potential for investigations of cell responses under ambient conditions. Evaluations that account only for the average response of cell monolayers mask the understanding of precise cell-molecular interactions or intracellular reactions at the level of individual cells. SPR/SPRi technology has attracted a great deal of attention for detecting the response of cell monolayers to various substances cultivated on the gold sensor chip. To unleash the full strength of SPRi technology in complex cell bio-systems, the applied SPR imaging system needs to be sufficiently effective to allow evaluation of a compound’s potency, specificity, selectivity, toxicity, and effectiveness at the level of the individual cell. In our studies, we explore the utility of high-resolution 2D-SPR imaging for real-time monitoring of intracellular translocation of protein kinase C (PKC), and detection of neuronal differentiation in live cells at the level of individual cells. The PC12 cell line, which is one of the most commonly used neuronal precursor cell lines for research on neuronal differentiation, was chosen as a nerve cell model. Two dimensional SPR (2D-SPR) signals/images are successfully generated. We have found that cells treated with the differentiation factor nerve growth factor (NGF) showed a remarkable enhancement of SPR response to stimulation by muscarine, a nonselective agonist of the muscarinic acetylcholine receptor.