Development of energy-transfer based Nano-probe system for biomolecular assay

Abstract

Recent development and advance on nanotechnology has brought new insight into the area of biotechnology. Highly sensitive functional nano-probe system based on energy transfer was described here for detecting genetic abnormalities and physiological disease. In the present study, two kinds of functional nano-probe systems were demonstrated for the detection of cancer related biomarkers. In the first approach, a designated nanoprobe based on energy transfer between quantum dots (QDs) and AuNPs was demonstrated for detecting proteolytic activity. Assay of proteases relies on modulations in the PL intensity of the nanoprobes; protease activity causes the cleavage of the peptide substrate on the nanoprobes, resulting in the recovery of the PL intensity of the nanoprobes from the quenching state. Compared to the traditional Forster energy transfer-based assay, QDs (donors) and AuNPs (acceptors) can offer some advantages including multiplexed, longer distance flexibility. We investigated their typical property in terms of the quenching efficiency, sensitivity and selectivity on a chip surface for multiplexed format. In the second approach, conformational change-induced energy transfer system called ‘molecular beacon’ nano-probe was employed for use of mutation-targeted cancer diagnosis. This energy transfer based molecular beacon probe was designed for the epidermal growth factor receptor (EGFR) that provides important insights for new drug resistance monitoring. We developed simple approaches with real time PCR assay and in situ single cell imaging technology as a tool for EGFR mutation screening by using designed molecular beacon probe. The ability of molecular beacon probes to detect specific target molecule without separation of unbound probes was able to provide a sensitive and selective assay in clinical applications. From these results, it is anticipated that the developed system will find various applications especially in clinical diagnosis.