Dual-Functional Plasmonic Photothermal Biosensors for Highly Accurate Severe Acute Respiratory Syndrome Coronavirus 2 Detection

Abstract

The ongoing outbreak of the novel coronavirus disease has spread globally and poses a threat to public health in more than 200 countries. Reliable laboratory diagnosis of the disease has been one of the foremost priorities for promoting public health interventions. The routinely used reverse transcription polymerase chain reaction (RT-PCR) is currently the reference method for COVID-19 diagnosis. However, it also reported a number of false-positive or -negative cases, especially in the early stages of the novel virus outbreak. In this work, a dual-functional plasmonic biosensor combining the plasmonic photothermal (PPT) effect and localized surface plasmon resonance (LSPR) sensing transduction provides an alternative and promising solution for the clinical COVID-19 diagnosis. The two-dimensional gold nanoislands (AuNIs) functionalized with complementary DNA receptors can perform a sensitive detection of the selected sequences from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through nucleic acid hybridization. For better sensing performance, the thermoplasmonic heat is generated on the same AuNIs chip when illuminated at their plasmonic resonance frequency. The localized PPT heat is capable to elevate the in situ hybridization temperature and facilitate the accurate discrimination of two similar gene sequences. Our dual-functional LSPR biosensor exhibits a high sensitivity toward the selected SARS-CoV-2 sequences with a lower detection limit down to the concentration of 0.22 pM and allows precise detection of the specific target in a multigene mixture. This study gains insight into the thermoplasmonic enhancement and its applicability in the nucleic acid tests and viral disease diagnosis.

Rapid, Ultrasensitive, and Quantitative Detection of SARS-CoV-2 Using Antisense Oligonucleotides Directed Electrochemical Biosensor Chip

“… 12 , 13 Although RT-PCR is excellent in terms of selectivity and sensitivity, it is time-intensive, requires highly qualified personnel, and can only be operated in a laboratory-based hospital with the accessibility of large stationary equipment and reagents. 14 , 15 These restrictions become major footraces for situations with resource shortages. The second category includes serological and immunological tests that primarily focus on the detection of antibodies developed in individuals because of their exposure to the virus.…”

Rapid Electrochemical Detection of Coronavirus SARS-CoV-2.

“…Additionally, some diagnostic tests have been designed to target the E gene to broadly detect coronavirus infections (bat SARS-like coronavirus and SARS-CoV) 20,38,39 . Besides these genes, other commonly used gene targets for detection of SARS-CoV-2 are the ORF1ab 17 and RdRp 40 genes.…”

Biomedical Science to Tackle the COVID-19 Pandemic: Current Status and Future Perspectives

“…As widely discussed in the literature, the SPR techniques are not restricted to planar multilayers [ 210 , 212 ]. On the contrary, metallic NPs with dimensions much smaller than the wavelength of the exciting light can ensure a more prominent signal due to their large extinction coefficient [ 210 ], the latter being heavily dependent on the dielectric constant, size and geometry of the NPs.…”

“…This assay proved to be rapid (10 min), sensitive, specific and reproducible. Furthermore, SARS-CoV2 was detected using sensor chips based on gold nanoislands (AuNIs) labeled with thiol-cDNA that acts as a capture probe when the complementary DNA is added [ 212 ] ( Figure 9 ). The hybridization process takes advantage from the photothermal effect made possible by the excitation of these AuNIs by a 32-mW laser at 532 nm wavelength applied in the normal incident angle avoiding, therefore, the use of an external source of heat.…”