Nucleotide-based nanoswitch and methods for the detection of antibodies and other analytes

A nucleotide-based nanoswitch system for detecting one or more targets in a sample, the system comprising a set of two or more oligonucleotide probes configured to provide a target binding-induced structural change of one or more of the oligonucleotide probes by a proximity-based hybridization reaction triggered by an increase in local concentration of the two or more oligonucleotide probes, wherein, upon contact of said oligonucleotide probes with the one or more targets, hybridization between hybridization sequences of said probes occurs, thereby producing a detectable change in a signal from one of the probes when the one or more of the oligonucleotide probes are contacted by the one or more targets, wherein said one or more targets are protein analytes, in particular an antibody or a protein antigen.