Discrimination Of Different Nucleobases And Serum Proteins Through Quantum Dot Based Pattern Sensing Array

Pattern sensor array, called “chemical noses/tongue,” is an artificial olfactory/gustatory based sensing array system. The array use differential receptor-analyte binding interactions provide an alternative to lock-and-key approach that use specific recognition processes, and this sensing mode is a simple, high-throughput, easy micro-assembly sensing way that shows great application prospect in the field of food safety, biomedical diagnosis, environmental monitoring.Currently, functional nanomaterials emerge as novel significant candidates for the development of pattern sensing technology. Semiconductor quantum dots(QDs), with their unique size dependent properties and flexible processibility, are widely used in as the area of nanosensors, bioimaging, catalysis. In this paper, QDs employed as excellent nanoprobe, we develop a new pattern sensing array to distinguish different biological molecules, such as nucleobases, human serum protein s. Two works have been performed as following:1. A novel exciton energy transfer-based fluorescence sensing array for the discrimination of different nucleobases was developed through target nucleobase-triggered self-assembly of quantum dots(QDs). Firstly, four QD nanoprobes with different ligand receptors, including mercaptoethylamine, L-cysteine, 2-dimethyl-aminethanethiol, and thioglycolic acid, were created to detect and identify nucleobase targets. The extent of particle assembly, induced by the analyte-triggered self-assembly of QDs, led to an exciton energy transfer effect between interparticles that gave a readily detectable fluorescence quenching and distinct fluorescence response patterns. These patterns are characteristic for each nucleobase and can be quantitatively differentiated by linear discriminate analysis. At the same time, a fingerprint based barcode was established to conveniently discriminate the nucleobases. Furthermore, this pattern sensing was successfully used to identify five rare bases. In this sensor array, QDs served as both selective recognition scaffolds and signal transduction elements for biomolecule target, provides a simple and label-free biosensing approach that shows great promise for biomedical applications.2. A novel fluorescence resonance energy tra nsfer(FRET)-based QDs pattern sensing array was developed for the discrimination of different human serum protein s through target-triggered disassembly of noncovalent amphiphilic polymer micelle. Firstly, four different surfactants(odium dodecyl sulfate, sodium N-lauroylsarcosine, cetyltrimethylammonium bromide, dodecyl trimethyl ammonium bromide) and four polyelectrolytes(sodium polymethacrylate, polystyrene sulfonate-maleic acid copolymer, polydiallyl dimethylammonium chloride, polyallylamine hydrochlo ride) were utilized to fabricate seven noncovalent amphiphilic polymer micelle s through supramolecular assemblies. The apolar interiors of micelle had sequestered FRET donor and acceptor pair(QDs and Texas Red? DHPE dye). The extent of nanomicelles disassembly, induced by five different human serum protein(immunoglobulin, human serum albumin, a-antitrypsin, fibrinogen, transferrin), lead to fluorescence quenching and give distinct fluorescence response patterns. These patterns can be quantitatively differentiated by linear discriminate analysis. The sensor array was successfully used to identify five human serum proteins. Furthermore, an unknown concentration of proteins were also effectively distinguish ed through absorption normalization algorithm. The design of the array is flexible and the signal is sensitive, it is expected to distinguish the actual samples of human serum proteins. The QDs micelles disassembly tachnology also showed good significance in the study of nanoassembly and biological micelles.