Biosensing nanoparticles are a particularly promising area for the development of new diagnostic tools; their small size and easily-modified surfaces allow for high specificity and sensitivity. When formulated as part of a biosensing system, nanoparticle probes act as an identifying receptor; when the target molecule binds to the nanoparticle receptor, it modifies the properties of the nanoparticle in a way that is detectable and measureable by a transducer. It is critical that the transducer can sufficiently and precisely characterize the biologic reaction. Tunable Resistive Pulse Sensing (TRPS) offers a rapid, reliable means of measuring the size, concentration, and charge of nanoparticles. qNano is useful for multiple stages of the biosensing process development; the instrument can rapidly confirm the characteristics of a) unfunctionalised nanoparticles, b) the surface functionalisation of the nanoparticle probe, and c) the resulting target-receptor conjugation.