Development of a miniaturized analytical device employing luminescence “contact” imaging detection for parvovirus B19 infection diagnosis

The Point-Of-Care (POC) approach is based on the development of portable analytical platforms suitable to perform analysis directly where it is required or where clinical care is delivered, allowing to streamline healthcare and to improve the clinical outcomes, since rapid testing should lead to rapid intervention. Parvovirus B19 (B19V) infection, which is mainly transmitted through respiratory route, is responsible for a wide spectrum of pathologies often misdiagnosed by clinicians. Most remarkably, B19V infection in pregnancy can lead to severe consequences such as fetal death. Thus, the availability of rapid and portable diagnostic systems would allow a prompt infection diagnosis and treatment with consequent reduction of adverse fetal outcomes. A miniaturized analytical device was developed for the diagnosis of parvovirus B19 (B19V) infection through the detection of viral DNA in serum samples. The method exploits the specificity and avidity of biospecific molecular recognition (i.e., hybridization of the target DNA with a peptide nucleic acid –PNA- probe) and ultrasensitive enzyme-catalyzed chemiluminescence detection. The device is based on three main components: specific PNA probes covalently immobilized on a glass surface, a microfluidics platform that allows for the delivery of reagents and a thermoelectrically cooled CCD camera employed for the sensitive detection of chemiluminescence emission by “contact imaging”. The method allowed reaching a limit of detection for B19V DNA of 50 fmol/mL, which is comparable with that obtained with standard laboratory methodologies, with an overall assay time of 30 min. In the future, a “hybrid” miniaturized device will be developed, in which both viral DNA and antibodies produced in response to the infection are simultaneously detected in the patient serum, thus leading to a more complete and predictive diagnosis.