Portable fiber-optic SPR platform for the detection of NS1-antigen for dengue diagnosis

• Published in: Biosensors & bioelectronics Vol. 196; p. 113720
• Main Authors: Gahlaut, Shashank K., Pathak, Anisha, Gupta, Banshi D., Singh, J.P.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.01.2022
• Subjects: Biosensing Techniques; Dengue; Dengue - diagnosis; Fiber Optic Technology; Humans; NS1 antigen; Optical fiber; Selectivity; Sensor; Silver; Surface Plasmon Resonance; Surface plasmons; NS1 antigen; Selectivity; Surface plasmons; Dengue; Sensor; Optical fiber
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2021.113720

Here, we present a portable, selective and cost-effective fiber-optic surface plasmon resonance (SPR) based platform for early detection of Dengue virus. NS1 protein was targeted as the biomarker of dengue. Antibody-antigen specific binding was exploited for NS1 antigen detection. The binding of antibody was assisted by a self-assembled monolayer of alkanethiols on the surface of silver-coated unclad fiber. A wavelength interrogation mode of SPR was utilized to detect NS1 antigen in the dynamic range of 0.2–2.0 μg/ml. The 40 nm thick silver coated optical fiber exhibited resonance wavelength around 500 nm and change in resonance wavelength was monitored for each attachment step on the fiber. The sensitivity at the lowest concentration of NS1 antigen was found to be 54.7 nm/(μg/ml). The limit of detection of the sensor was found to be 0.06 μg/ml, which lies in the physiological range of NS1 protein present in the infected blood, hence the present technique may provide a very early detection advantage. Real blood serum samples were also successfully tested on the set-up, confirming compatibility with the conventional methods. The presented field-deployable platform has wide applications in mass monitoring of dengue, such as during outbreaks and epidemics. •A portable fiber optic-SPR platform demonstrated for early stage Dengue detection.•Antibody-antigen specific binding was utilized for selective detection of NS1 antigen.•A mixed self-assembled monolayer (1-HT + 11-MUA) immobilized to bind anti-NS1 antibody.•The probe was also tested on clinical NS1 positive blood samples.•The sensitivity and limit of detection were determined to be 54.7 nm/(μg/ml) and 0.066 μg/ml respectively.