Viral infections are among the main causes of morbidity and mortality of humans; sensitive and specific diagnostic methods for the rapid identification of viral pathogens are required. Surface-enhanced Raman spectroscopy (SERS) is one of the most promising techniques for routine analysis due to its excellent sensitivity, simple and low-cost instrumentation and minimal required sample preparation. The outstanding sensitivity of SERS is achieved due to tiny nanostructures which must be assembled before or during the analysis. As for specificity, it may be provided using recognition elements. Antibodies, complimentary nucleic acids and aptamers are the most usable recognition elements for virus identification. Here, SERS-based biosensors for virus identification with oligonucleotides as recognition elements are reviewed, and the potential of these biosensors is discussed.

During the COVID-19 pandemic, the development of sensitive and rapid techniques for detection of viruses have become vital. Surface-enhanced Raman scattering (SERS) is an appropriate tool for new techniques due to its high sensitivity. SERS materials modified with short-structured oligonucleotides (DNA aptamers) provide specificity for SERS biosensors. Existing SERS-based aptasensors for rapid virus detection are either inapplicable for quantitative determination or have sophisticated and expensive construction and implementation. In this paper, we provide a SERS-aptasensor based on colloidal solutions which combines rapidity and specificity in quantitative determination of SARS-CoV-2 virus, discriminating it from the other respiratory viruses.

Rapid and reliable techniques for virus identification are required in light of recurring epidemics and pandemics throughout the world. Several techniques have been distributed for testing the flow of patients. Polymerase chain reaction with reverse transcription is a reliable and sensitive, though not rapid, tool. The antibody-based strip is a rapid, though not reliable, and sensitive tool. A set of alternative tools is being developed to meet all the needs of the customer. Surface-enhanced Raman spectroscopy (SERS) provides the possibility of single molecule detection taking several minutes. Here, a multiplex lithographic SERS aptasensor was developed aiming at the detection of several respiratory viruses in one pot within 17 min. The four labeled aptamers were anchored onto the metal surface of four SERS zones; the caught viruses affect the SERS signals of the labels, providing changes in the analytical signals. The sensor was able to decode mixes of SARS-CoV-2 (severe acute respiratory syndrome coronavirus two), influenza A virus, respiratory syncytial virus, and adenovirus within a single experiment through a one-stage recognition process.

In this paper, we propose a technology for the rapid and sensitive detection of the whole viral particles of SARS-CoV-2 using double-labeled DNA aptamers as recognition elements together with the SERS method for detecting the optical response. We report on the development of a SERS-aptasensor based on a reproducible lithographic SERS substrate, featuring the combination of high speed, specificity, and ultrasensitive quantitative detection of SARS-CoV-2 virions. The sensor makes it possible to identify SARS-CoV-2 in very low concentrations (the limit of detection was 100 copies/mL), demonstrating a sensitivity level comparable to the existing diagnostic golden standard—the reverse transcription polymerase chain reaction.

Tuberculosis remains a serious global public health challenge and requires the development of rapid, sensitive, and specific diagnostic tools for effective treatment and disease control. Bioimaging reporters are promising diagnostic tools that exploit the unique biochemical properties of Mycobacterium tuberculosis for real-time detection of viable cells from clinical samples. Moreover, these methods offer significant advantages over the conventional methods currently used in practice, including reduced assay time, increased specificity, and the ability to discriminate viable cells from dead cells. In this review, we highlight reporters of a different nature that the enable direct detection of Mycobacterium tuberculosis, eliminating complex sample preparation. Such reporters could serve as powerful tools in fluorescence microscopy, provide alternative strategies for automated culture-based diagnostic systems, and offer new approaches for developing point-of-care methods and diagnostic devices suitable for clinical practice.

Trehalose probes seem to be a promising area of tuberculosis diagnosis, these probes are capable of selectively penetrating Mycobacterium tuberculosis. These probes generate a fluorescent signal, enabling detection of mycobacteria. To analyze the current state of knowledge and prospects of trehalose probes as a new approach for rapid detection of Mycobacterium tuberculosis, a systematic review of scientific literature was conducted. The main types of probes include fluorogenic probes, "fluorophore-quencher" based probes, and photoactivatable probes. Trehalose probes enable selective detection of mycobacteria due to specific trehalose uptake and incorporation into the cell wall, followed by fluorescence activation. These probes allow for the detection of mycobacteria in sputum samples without complex sample preparation or washing. The method allows differentiation of viable and non-viable cells and can also be applied for drug susceptibility testing.