Lectin affinity based elemental labeling with hybridization chain reaction for the sensitive determination of avian influenza A (H9N2) virions

Pathogen detection via inductively coupled plasma mass spectrometry analysis with nanoparticles

Infections caused by viruses and bacteria pose a significant threat to global public health, emphasizing the critical importance of timely and precise detection methods. Inductively coupled plasma mass spectrometry (ICP-MS), a contemporary approach for pathogen detection, offers distinct advantages such as high sensitivity, a wide linear range, and multi-index capabilities. This review elucidates the underexplored application of ICP-MS in conjunction with functional nanoparticles (NPs) for the identification of viruses and bacteria. The review commences with an elucidation of the underlying principles, procedures, target pathogens, and NP requirements for this innovative approach. Subsequently, a thorough analysis of the advantages and limitations associated with these techniques is provided. Furthermore, the review delves into a comprehensive examination of the challenges encountered when utilizing NPs and ICP-MS for pathogen detection, culminating in a forward-looking assessment of the potential pathways for advancement in this domain. Thus, this review contributes novel perspectives to the field of pathogen detection in biomedicine by showcasing the promising synergy of ICP-MS and NPs.

Label-free detection of biomolecules using inductively coupled plasma mass spectrometry (ICP-MS)

Bioassays using inductively coupled plasma mass spectrometry (ICP-MS) have gained increasing attention because of the high sensitivity of ICP-MS and the various strategies of labeling biomolecules with detectable metal tags. The classic strategy to tag the target biomolecules is through direct antibody-antigen interaction and DNA hybridization, and requires the separation of the bound from the unbound tags. Label-free ICP-MS techniques for biomolecular assays do not require direct labeling: they generate detectable metal ions indirectly from specific biomolecular reactions, such as enzymatic cleavage. Here, we highlight the development of three main strategies of label-free ICP-MS assays for biomolecules: (1) enzymatic cleavage of metal-labeled substrates, (2) release of immobilized metal ions from the DNA backbone, and (3) nucleic acid amplification-assisted aggregation and release of metal tags to achieve amplified detection. We briefly describe the fundamental basis of these label-free ICP-MS assays and discuss the benefits and drawbacks of various designs. Future research is needed to reduce non-specific adsorption and minimize background and interference. Analytical innovations are also required to confront challenges faced by in vivo applications.

Elemental Mass Spectrometry and Fluorescence Dual-Mode Strategy for Ultrasensitive Label-Free Detection of HBV DNA

This work reported a simple and ultrasensitive label-free method for the detection of hepatitis B virus (HBV) DNA by combining hyperbranched rolling circle amplification (HRCA) with dual-mode detection by inductively coupled plasma mass spectrometry (ICP-MS) and fluorescence using ruthenium complex [Ru(bpy)₂dppz]²⁺ (bpy = 2,2'-bipyridine, dppz = dipyrido [3,2-a:2',3'-c] phenazine) as a dual functional probe. An HBV DNA-initiated HRCA system was designed to realize the highly efficient amplification of HBV DNA with the generation of a mass of dsDNA. Also, the [Ru(bpy)₂dppz]²⁺ probe was then added to intercalate into the dsDNA products, resulting in strong fluorescence recovery of the probe for fluorescence detection. Meanwhile, using a biotin-modified primer in HRCA, the dsDNA-[Ru(bpy)₂dppz]²⁺ complexes could be captured by the avidin-coated 96-well plates, and the captured [Ru(bpy)₂dppz]²⁺ probe was later desorbed by acid for ICP-MS detection. The linear range of the proposed method was 3.5-200 amol L^-1 and the limit of detection (LOD) was 1 amol L^-1 for ICP-MS detection, while the linear range was 20-500 amol L^-1 and the LOD was 9.6 amol L^-1 for fluorescence detection. The developed method was applied to human serum sample analysis, and the analytical results coincided very well with those obtained by the real-time polymerase chain reaction (PCR) method. The developed dual-mode label-free detection method was ultrasensitive, simple, and accurate, showing great potential for therapeutic monitoring of HBV infection.

Understanding the relationship between viral infections and trace elements from a metallomics perspective: implications for COVID-19

Recently, the World Health Organization (WHO) declared a pandemic situation due to a new viral infection (COVID-19) caused by a novel virus (Sars-CoV-2). COVID-19 is today the leading cause of death from viral infections in the world. It is known that many elements play important roles in viral infections, both in virus survival, and in the activation of the host's immune system, which depends on the presence of micronutrients to maintain the integrity of its functions. In this sense, the metallome can be an important object of study for understanding viral infections. Therefore, this work presents an overview of the role of trace elements in the immune system and the state of the art in metallomics, highlighting the challenges found in studies focusing on viral infections.

The Recent Development of Hybridization Chain Reaction Strategies in Biosensors

With the continuous development of biosensors, researchers have focused increasing attention on various signal amplification strategies to pursue superior performance for more applications. In comparison with other signal amplification strategies, hybridization chain reaction (HCR) as a powerful signal amplification technique shows its certain charm owing to nonenzymatic and isothermal features. Recently, on the basis of conventional HCR, this technique has been developed and improved rapidly, and a variety of HCR-based biosensors with excellent performance have been reported. Herein, we present a systematic and critical review on the research progress of HCR in biosensors in the last five years, including the newly developed HCR strategies such as multibranched HCR, migration HCR, localized HCR, in situ HCR, netlike HCR, and so on, as well as the combination strategies of HCR with isothermal signal amplification techniques, nanomaterials, and functional DNA molecules. By illustrating some representative works, we also summarize the advantage and challenge of HCR in biosensors, and offer a deep discussion of the latest progress and future development trends of HCR in biosensors.

Bio-barcode detection technology and its research applications: A review

With the rapid development of nanotechnology, the bio-barcode assay (BCA), as a new diagnostic tool, has been gradually applied to the detection of protein and nucleic acid targets and small-molecule compounds. BCA has the advantages of high sensitivity, short detection time, simple operation, low cost, good repeatability and good linear relationship between detection results. However, bio-barcode technology is not yet fully formed as a complete detection system, and the detection process in all aspects and stages is unstable. Therefore, studying the optimal reaction conditions, optimizing the experimental steps, exploring the multi-residue detection of small-molecule substances, and preparing immuno-bio-barcode kits are important research directions for the standardization and commercialization of BCA. The main theme of this review was to describe the principle of BCA, provide a comparison of its application, and introduce the single-residue and multi-residue detection of macromolecules and single-residue detection of small molecules. We also compared it with other detection methods, summarized its feasibility and limitations, expecting that with further improvement and development, the technique can be more widely used in the field of stable small-molecule and multi-residue detection.

Dual-mode detection of avian influenza virions (H9N2) by ICP-MS and fluorescence after quantum dot labeling with immuno-rolling circle amplification

Avian influenza virus (AIVs), hosted in poultry, are the pathogens of many poultry diseases and human infections, which bring huge losses to the poultry breeding industry and huge panic to society. Therefore, it is of great significance to establish accurate and sensitive detection methods for AIVs. In this work, a dual-mode detection method based on immuno-rolling circle amplification (immuno-RCA) and quantum dots (QDs) labeling for inductively coupled plasma mass spectrometry (ICP-MS) and fluorescence detection of H9N2 AIV was developed. The dual-mode detection of the QDs by ICP-MS and fluorescence is used to achieve mutual verification within the analysis results, thus improving the accuracy of the method. With the immuno-RCA, the sensitivity of the method was increased by two orders of magnitude. The limit of detection of the proposed method is 17 ng L^-1 and 61 ng L^-1, and the linear range of the proposed method is 0.05-5 ng mL^-1 and 0.1-5 ng mL^-1 with ICP-MS and fluorescence detection, respectively. The relative standard deviation (n = 7) is 4.9% with ICP-MS detection and 3.1% with fluorescence detection. Furthermore, the proposed method was applied to the analysis of chicken serum samples, no significant different was found for two modes detection and the recoveries of the spiking experiments are acceptable, indicating that the method has good practical potential for real sample analysis.