The present disclosure is directed to aptamers comprising a detectable marker situated at an internal location within the aptamer, use of the aptamers to, e.g., detect target analytes, and methods of making the aptamers. In exemplary embodiments, methods of the disclosure comprise contacting the target analyte with an aptamer comprising a detectable marker situated at an internal location within the aptamer, wherein the contacting results in binding of the target analyte to the aptamer, wherein target analyte binding to the aptamer results in restriction of internal rotation of the marker, resulting in a detectable change in the marker.

The present disclosure is directed to spherical nucleic acids (SNAs) comprising a nanoparticle core and an oligonucleotide, use of the SNAs to, e.g., detect target analytes, and methods of making the SNAs. In various embodiments, the target analyte is detected using the nanoparticle core, the oligonucleotide, or both. In some embodiments, the oligonucleotide comprises a detectable marker situated at an internal location within the oligonucleotide. In some aspects, the disclosure provides methods for detecting a target analyte comprising the step of contacting the target analyte with a spherical nucleic acid (SNA) and an agent, the SNA comprising a protein core and an oligonucleotide attached thereto, wherein the contacting of the protein core with the target analyte results in a change in the target analyte that is detectable by the agent, thereby detecting the target analyte.

The present disclosure is directed to spherical nucleic acids (SNAs) comprising a nanoparticle core and an oligonucleotide, use of the SNAs to, e.g., detect target analytes, and methods of making the SNAs. In various embodiments, the target analyte is detected using the nanoparticle core, the oligonucleotide, or both. In some embodiments, the oligonucleotide comprises a detectable marker situated at an internal location within the oligonucleotide. In some aspects, the disclosure provides methods for detecting a target analyte comprising the step of contacting the target analyte with a spherical nucleic acid (SNA) and an agent, the SNA comprising a protein core and an oligonucleotide attached thereto, wherein the contacting of the protein core with the target analyte results in a change in the target analyte that is detectable by the agent, thereby detecting the target analyte.

An electrochemical aptamer-based (E-AB) sensor is disclosed. The sensor is a closed bipolar electrode having a first end and a second end. The first end comprises an electrochromic material. The second end comprises an electrocatalyst and an oligonucleotide aptamer tethered to the second end. Further, the oligonucleotide aptamer is labelled with a redox indicator.

An electrochemical aptamer-based (E-AB) sensor is disclosed. The sensor is a closed bipolar electrode having a first end and a second end. The first end comprises an electrochromic material. The second end comprises an electrocatalyst and an oligonucleotide aptamer tethered to the second end. Further, the oligonucleotide aptamer is labelled with a redox indicator.

The present disclosure provides a kit for preparing a library of nucleic acids. The kit includes first and second oligonucleotide, each having a tail sequence, a common sequence, and at least one of a unique identifier sequence, and a variable length punctuation mark. The kit further includes a first primer having a first sample identifier sequence and a first priming sequence at a 3′ end of the first primer. The first priming sequence includes the tail sequence of the first oligonucleotide. The kit further includes a second primer having a second sample identifier sequence and a second priming sequence at a 3′ end of the second primer. The second priming sequence is complimentary to the second tail sequence of the second oligonucleotide.

The present disclosure provides a kit for preparing a library of nucleic acids. The kit includes first and second oligonucleotide, each having a tail sequence, a common sequence, and at least one of a unique identifier sequence, and a variable length punctuation mark. The kit further includes a first primer having a first sample identifier sequence and a first priming sequence at a 3′ end of the first primer. The first priming sequence includes the tail sequence of the first oligonucleotide. The kit further includes a second primer having a second sample identifier sequence and a second priming sequence at a 3′ end of the second primer. The second priming sequence is complimentary to the second tail sequence of the second oligonucleotide.

A method for direct quantification of nucleic acids in real time qPCR. The invention discloses a method for specific quantification of nucleic acids in real time qPCR. The disclosed invention can be achieved in three ways; 1) using a modified primer for qPCR quantification; 2) using strand displacement based probes for qPCR quantification; 3) using label-free endonuclease probe for qPCR quantification. The mechanism of quantification is based on the fact that, DNA, RNA or modified oligonucleotide based light-up dye-aptamer system, where dye is not fluorescent in free state but its fluorescence increases multi-fold when it binds to its specific aptamer.

A method for direct quantification of nucleic acids in real time qPCR. The invention discloses a method for specific quantification of nucleic acids in real time qPCR. The disclosed invention can be achieved in three ways; 1) using a modified primer for qPCR quantification; 2) using strand displacement based probes for qPCR quantification; 3) using label-free endonuclease probe for qPCR quantification. The mechanism of quantification is based on the fact that, DNA, RNA or modified oligonucleotide based light-up dye-aptamer system, where dye is not fluorescent in free state but its fluorescence increases multi-fold when it binds to its specific aptamer.

The present invention relates to a metal ion-start DNA polymerase switch, a composition for isothermal polymerase amplification containing the same, and an isothermal amplification method using the metal ion-start DNA polymerase switch. The metal ion-start DNA polymerase switch according to the present invention may comprise: a binding module composed of TQ30 aptamer; a locking or unlocking module; and a catalytic module connecting between the binding module and the locking or unlocking module and composed of DNAzyme.