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| Image created by Dr. Michael J. Miller |
Dengue is a serious global health concern with a large population around the world facing the risk of getting infected. Early diagnosis of dengue is the key to prevent deterioration of a patient’s health. However, conventional diagnostic tools like nucleic acid detection using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a time taking proess and it also requires expensive equipments and reagents for the diagnosis of dengue.
These types of common diseases require a rapid, scalable and point-of-care diagnosis to be implemented at the community level and to reduce the workload of healthcare professionals. Understanding this, the GLancing Angle Deposition (GLAD) research group at IIT Delhi’s Physics Department has developed a handheld Surface Enhanced Raman Spectroscopy (SERS) based platform for early diagnosis of dengue virus. It also gives dengue test results within one hour (rapid diagnosis).
The handheld device has been succsessfully tested on the clinical blood samples collected from hundreds of individuals in collaboration with ICMR-National Institute of Malaria Research (NIMR), New Delhi.
Principal Investigator of the project and Professor in the Department of Physics, IIT Delhi, Prof. J.P. Singh’s research group is known for the synthesis of nanoscultptured thin films using a specialized technique called GLAD. This technique was employed to fabricate silver nanorods array based SERS active biosensors in order to detect pathogens. Only 2 microlitres of a diluted serum was dropcasted on the SERS substartes and Raman spectra were collected by flashing 785 nm laser beam through the device. All the data were fed in a statistical tool principal component analyzer (PCA) software. The intergrated device was able to clearly differentiate the three sets of blood samples; dengue positive, negative and healthy. This method provides a sensitive, rapid, and field deployable diagnosis of dengue at the early stage.
The research work was funded by IMPRINT India program of the Ministry of Education with New Age Instruments and Materials Pvt Ltd as the industry partner. The research was published in the journal Analytical Chemistry 92, 2527-2534 (2020).
The detection and distinction of human immunodeficiency virus (HIV-1) was also carried out in collaboration with ICMR-National AIDS Research Institute (NARI), Pune through the handheld SERS based platform. Binding of viruses directly on Ag nanorods without using antibodies or intermediate reagents was successfully demonstrated. The SERS platform was capable of distinguishing different tropic strains of HIV-1 suggesting tropism-based detection. The SERS based platform gives HIV-1 test results within an hour.
Speaking of the hand-held device, the project’s PI, Prof. J.P. Singh, IIT Delhi said, “This ultrasensitive and handy device has wide range of applications in the early-stage on-site detection of viral diseases and can produce the final report of investigation within an hour.” The research work was published recently in journal Colloids and Surfaces B: Biointerfaces 198, 111477 (2021).