This disclosure relates to biosensors, and in particular, biosensors based on nucleic acid cleaving enzymes such as ribonucleotide-cleaving DNAzymes for the detection of analytes, and methods of use.

The present invention provides modified oligonucleotides and methods for their use in the detection of nucleic acids. The oligonucleotides and methods find particular application in amplifying and/or detecting areas of genetic variation in target nucleic acid sequences.

The present invention provides modified oligonucleotides and methods for their use in the detection of nucleic acids. The oligonucleotides and methods find particular application in amplifying and/or detecting areas of genetic variation in target nucleic acid sequences.

The present application is directed to biosensors and methods for detecting a microorganism target in a sample using a mechanically interlocked nucleic acid catanane, wherein an enzyme from the microorganism target or that is activated by a molecule from the microorganism target cleaves a linkage in a first single-stranded nucleic acid ring of the catanane structure, allowing rolling-circle amplification to occur and the presence of rolling-circle amplification products indicates the presence of the microorganism in the sample.

The present application is directed to biosensors and methods for detecting a microorganism target in a sample using a mechanically interlocked nucleic acid catanane, wherein an enzyme from the microorganism target or that is activated by a molecule from the microorganism target cleaves a linkage in a first single-stranded nucleic acid ring of the catanane structure, allowing rolling-circle amplification to occur and the presence of rolling-circle amplification products indicates the presence of the microorganism in the sample.

A method of DNAzyme activity in a fluid by a sensor that is manufactured as follows. A method of manufacturing a fiber optic surface plasmon resonance sensor tip for sensing DNAzyme activity in a fluid, the method comprising, a) providing an fiber optic surface plasmon resonance sensor (FO-SPR) tip comprising at least one first single strand DNA with distinct sequence (immobilized on the sensing surface of said the fiber optic surface plasmon resonance sensor tip, b) providing gold nanoparticles (AuNPs) comprising a second single strand DNA with distinct sequence immobilized on said the gold nanoparticles, c) providing a third distinct DNA sequence ligation template for said first and second single strand for DNA hybridizing the third distinct DNA sequence ligation template in part with said the first single strand DNA and in part with the second single strand DNA to form one FO-SPR probe and AuNP-probe complex and d) providing a selected ligase to ligate together to a selected single strand DNA construct between AuNP and FO-SPR adapted to function as a selected DNAzyme FO-SPR-AuNP-probe. An aspect of present invention is a surface plasmon resonance (SPR) real-time monitoring system of NAzyme cleavage activity manufactured by ligation of a metallic nanoparticle (NP)-labelled DNA-sequences to a SPR sensing surface and yet more particular by ligation of AuNP-labelled DNA-sequences to a FO-SPR gold surface. Furthermore, incorporation of temporary inactivating the NAzyme with an inhibitor strand or a NAzyme blocking DNA sequence, containing an internal loop for target recognition independent of the catalytic activity from the NAzyme binding arms in the SPR sensor, e.g. FO-SPR sensor, allows real-time monitoring system of NAzyme cleavage activity in function of binding of selected targets (peptides, polypeptides, protein, small molecules, nucleotides, fat groups) to the internal loop of said the inhibitor strand.

A method of DNAzyme activity in a fluid by a sensor that is manufactured as follows. A method of manufacturing a fiber optic surface plasmon resonance sensor tip for sensing DNAzyme activity in a fluid, the method comprising, a) providing an fiber optic surface plasmon resonance sensor (FO-SPR) tip comprising at least one first single strand DNA with distinct sequence (immobilized on the sensing surface of said the fiber optic surface plasmon resonance sensor tip, b) providing gold nanoparticles (AuNPs) comprising a second single strand DNA with distinct sequence immobilized on said the gold nanoparticles, c) providing a third distinct DNA sequence ligation template for said first and second single strand for DNA hybridizing the third distinct DNA sequence ligation template in part with said the first single strand DNA and in part with the second single strand DNA to form one FO-SPR probe and AuNP-probe complex and d) providing a selected ligase to ligate together to a selected single strand DNA construct between AuNP and FO-SPR adapted to function as a selected DNAzyme FO-SPR-AuNP-probe. An aspect of present invention is a surface plasmon resonance (SPR) real-time monitoring system of NAzyme cleavage activity manufactured by ligation of a metallic nanoparticle (NP)-labelled DNA-sequences to a SPR sensing surface and yet more particular by ligation of AuNP-labelled DNA-sequences to a FO-SPR gold surface. Furthermore, incorporation of temporary inactivating the NAzyme with an inhibitor strand or a NAzyme blocking DNA sequence, containing an internal loop for target recognition independent of the catalytic activity from the NAzyme binding arms in the SPR sensor, e.g. FO-SPR sensor, allows real-time monitoring system of NAzyme cleavage activity in function of binding of selected targets (peptides, polypeptides, protein, small molecules, nucleotides, fat groups) to the internal loop of said the inhibitor strand.

The present invention relates to a composition for temperature sensors including graphene oxide, DNAzyme and PNA, a temperature sensing method and a kit using the same. In the present invention, when the DNAzyme/PNA duplex is dissociated at a certain temperature, graphene oxide adsorbs PNA with excellent selectivity and irreversibility, enabling recall of temperature, to permit delayed color development in the time of need. Also, the target temperature can be easily and quickly detected with the naked eye through the color change of the colorimetric reagent, and the thermosensor is technically convenient and easy to apply, so it can be used in various biological applications. Moreover, it can be used as a barcode (on/off) system using a combination of PNA probes with various lengths, and thus can be broadly applied to sensing a diverse range of temperatures.

The present invention relates to a composition for temperature sensors including graphene oxide, DNAzyme and PNA, a temperature sensing method and a kit using the same. In the present invention, when the DNAzyme/PNA duplex is dissociated at a certain temperature, graphene oxide adsorbs PNA with excellent selectivity and irreversibility, enabling recall of temperature, to permit delayed color development in the time of need. Also, the target temperature can be easily and quickly detected with the naked eye through the color change of the colorimetric reagent, and the thermosensor is technically convenient and easy to apply, so it can be used in various biological applications. Moreover, it can be used as a barcode (on/off) system using a combination of PNA probes with various lengths, and thus can be broadly applied to sensing a diverse range of temperatures.

The present invention relates to a composition for detecting nucleic acid comprising duplex molecular beacon and graphene oxide and a colorimetric signal enhancement method of detecting nucleic acid using the same. According to the composition, kit and method for detecting nucleic acid of the present invention, a complex can be formed by adsorbing a single strand having a DNAzyme sequence dissociated from the conjugate of a duplex molecular beacon and a target nucleic acid to the graphene oxide surface, and separated, and a colorimetric signal amplified therefrom can be induced, so that a very low concentration of target nucleic acid can be detected with high efficiency and the target nucleic acid can be detected quickly and easily in seconds. Therefore, a new colorimetric target nucleic acid detection system capable of point of care testing (POCT) can be provided.