Fabrication and deployment of nanoscale fluorescent intracellular probes

Nanofabrication is an attractive tool for precise construction of micro/nanostructures to realize fluorescence sensors that may overcome problems related to use of free dyes for biological analysis. Sensor films deposited on optically-functional nanotemplates (<300 nm) are proposed as intracellular chemical sensors that provide an internal standard and stable separation of host from toxic foreign materials. Fluorescent nanoparticles were used as templates and intensity references for an oxygen-sensitive fluorophore Ru(dpp) and a potassium-binding dye (PBFI). Nanoassembled films on particles were characterized in terms of response to target analytes, and an efficient method of delivery to cytosol was developed using a polycationic coating. These findings suggest that self-assembled nanoparticle sensors may be easily produced and employed as useful tools for real-time cellular analysis.