Abstract: The invention provides a method for detecting the presence of a target nucleic acid analyte, for example a pathogen or virus nucleic acid, in a sample using oligonucleotide probe-functionalised nanoparticles, where hybridisation of at least three different oligonucleotide probes to at least three different target sequences in the target analyte causes agglomeration of the nanoparticles and a visible colour change. The invention also provides a population of such oligonucleotide probe-functionalised nanoparticles and a related kit for detection of a target nucleic acid analyte.

Abstract: The present invention provides a method for detecting the presence or absence of a target analyte in a test sample, comprising the steps: i) providing a plurality of detector nanoparticles comprising a first detector nanoparticle functionalised with a first probe specific for a first region of a target analyte and a second detector nanoparticle functionalised with a second probe specific for a second region of said target analyte; and ii) contacting said detector nanoparticles with a test sample under conditions suitable for the binding of the specific probes to the target analyte, wherein target analyte-induced agglomeration of the detector nanoparticles permits the release of a detectable signal means from a signal reservoir. Also provided are related devices and systems for performing the method of the invention.