Point-of-Use Nanobiosensor for Detection of Dengue Virus NS1 Antigen in Adult Aedes aegypti: A Potential Tool for Improved Dengue Surveillance.

Dengue virus (DENV) and its primary mosquito vectors Aedes spp. have spread to every continent except Antarctica, causing outbreaks and autochthonous transmission in previously disease-free regions. Recently, the spread of other arboviruses carried by invasive Aedes spp., such as Chikungunya and Zika, seem to be following similar trends as DENV and have renewed interest in monitoring and modeling arboviruses within mosquito vectors. Unfortunately, current commercially available detection methods are designed for the diagnosis of DENV in humans or are too expensive and complex for sustainable monitoring. We report a novel electronic nanobiosensor utilizing a single-walled carbon nanotube networks chemiresistor transducer functionalized with antidengue NS1 monoclonal antibodies for rapid detection of the dengue nonstructural protein 1 (NS1). NS1 is a highly conserved protein secreted at high concentrations during viral replication and is a biomarker for DENV infection. NS1 was successfully detected in spiked adult Aedes aegypti homogenate over a broad dynamic range with high sensitivity and selectivity. The biosensor is compatible with "gold-standard" adult mosquito field-collection protocols and generates electronic data that can be readily stored or wirelessly transmitted. Thus, it has potential for remote and real-time monitoring of wild mosquito populations.

Salivary Detection of Dengue Virus NS1 Protein with a Label-Free Immunosensor for Early Dengue Diagnosis.

Dengue virus (DENV) is a highly pathogenic, arthropod-borne virus transmitted between people by Aedes mosquitoes. Despite efforts to prevent global spread, the potential for DENV epidemics is increasing world-wide. Annually, 3.6 billion people are at risk of infection. With no licensed vaccine, early diagnosis of dengue infection is critical for clinical management and patient survival. Detection of DENV non-structural protein 1 (NS1) is a clinically accepted biomarker for the early detection of DENV infection. Unfortunately, virtually all of the laboratory and commercial DENV NS1 diagnostic methods require a blood draw for sample analysis, limiting point-of-care diagnostics and decreases patient willingness. Alternatively, NS1 in human saliva has been identified for the potential early diagnosis of DENV infection. The collection of saliva is simple, non-invasive, painless, and inexpensive, even by minimally trained personnel. In this study, we present a label-free chemiresistive immunosensor for the detection of the DENV NS1 protein utilizing a network of single-walled carbon nanotubes functionalized with anti-dengue NS1 monoclonal antibodies. NS1 was successfully detected in adulterated artificial human saliva over the range of clinically relevant concentrations with high sensitivity and selectivity. It has potential application in clinical diagnosis and the ease of collection allows for self-testing, even within the home.

A heparin-functionalized carbon nanotube-based affinity biosensor for dengue virus.

Dengue virus is an arthropod-borne virus transmitted primarily by Aedes mosquitos and is major cause of disease in tropical and subtropical regions. Colloquially known as Dengue Fever, infection can cause hemorrhagic disorders and death in humans and non-human primates. We report a novel electronic biosensor based on a single-walled carbon nanotube network chemiresistive transducer that is functionalized with heparin for low-cost, label-free, ultra-sensitive, and rapid detection of whole dengue virus (DENV). Heparin, an analog of the heparan sulfate proteoglycans that are receptors for dengue virus during infection of Vero cells and hepatocytes, was used for the first time in a biosensor as a biorecognition element instead of traditional antibody. Detection of DENV in viral culture supernatant has similar sensitivity as the corresponding viral titer in phosphate buffer despite the presence of growth media and Vero cell lysate. The biosensor demonstrated sensitivity within the clinically relevant range for humans and infected Aedes aegypti. It has potential application in clinical diagnosis and can improve point-of-care diagnostics of dengue infection.