Engineered Core-Shell Multifunctional Nano-Tracer in Raman-Silent Region with Highly Retained Affinity to Enhance Lateral Flow Immunoassays

Multifunctional magnetic tags with photocatalytic and enzyme-mimicking properties for constructing a sensitive dual-readout ELISA

ELISA has become the gold standard for detecting harmful substances due to its specific antibody recognition and sensitive enzyme-catalyzed reactions. In this study, multifunctional magnetic Prussian blue nanolabels (MPBNs) were synthesized using a simple gentle two-step method to achieve a dual-readout mode. The MPBNs provide a sensitive colorimetric signal by efficiently catalyzing the oxidation of TMB and exhibit prominent photocatalytic degradation activity towards Rhodamine B (RhB). Supplemented by the quenching effect of oxTMB, the fluorescence was enabled to serve as a sensitive second signal. The magnetic property of the labels facilitates the separation and enrichment of the target, thereby improving sensitivity. Utilizing the versatile MPBNs, the visual limit of detection (vLOD) for Staphylococcus aureus is as low as 100 CFU/mL, with a quantitative analysis range of 102-108 CFU/mL. The introduction of photocatalytic reactions into immunoassay has opened up a new signal response system with strong momentum for development and application.

Raman silent region - based method for detection of pesticides with cyano group

Based on the fact that not all chemical substances possess good Raman signals, this article focuses on the Raman silent region signals of pesticides with cyano group. Under the optimized conditions of methanol-water (1:1, v/v) as the solvent, irradiation at 302 nm light source for 20 min, and the use of 0.5 mol/L KI as the aggregating agent, Surface-enhanced Raman spectroscopy (SERS) method for azoxystrobin detection was developed by the Raman silent region signal of 2230 cm-1, and verified by detecting the spiked grapes with different concentrations of azoxystrobin. Other four pesticides with cyano group also could be identified at the peak of 2180 cm-1, 2205 cm-1, 2125 cm-1, and 2130 cm-1 for acetamiprid, phoxim, thiacloprid and cymoxanil, respectively. When azoxystrobin or acetamiprid was mixed respectively with chlorpyrifos without cyano group, their SERS signals in the Raman silent region of chlorpyrifos were not interfered, while mixed with cymoxanil in different ratios (1:4, 1:1 and 4:1), respectively, each two pesticides with cyano group could be distinguished by the changes in the Raman silent region. In further, four pesticides with or without cyano group were mixed together in 1:1:1:1 (acetamiprid, cymoxanil, azoxystrobin chlorpyrifos), and each pesticide still could be identified even at 0.5 mg/L. The results showed that the SERS method combined with UV irradiation may provide a new way to monitor the pesticides with C≡N performance in the Raman silent region without interference from the food matrix.

Application of Surface-Enhanced Raman Spectroscopy Combined with Immunoassay for the Detection of Adrenoceptor Agonists

Rapid, sensitive, and accurate detection of adrenoceptor agonists is a significant research topic in the fields of food safety and public health. Immunoassays are among the most widely used methods for detecting adrenoceptor agonists. In recent years, surface-enhanced Raman spectroscopy combined with immunoassay (SERS-IA) has become an effective technique for improving detection sensitivity. This review focuses on the innovation of Raman reporter molecules and substrate materials for the SERS-IA of adrenoceptor agonists. In addition, it also investigates the challenges involved in potentially applying SERS-IA in the detection of adrenoceptor agonists. Overall, this review provides insight into the design and application of SERS-IA for the detection of adrenoceptor agonists, which is critical for animal-derived food safety and public health.

SERS-based microdevices for use as in vitro diagnostic biosensors

Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology.

A dual-mode lateral flow immunoassay by ultrahigh signal-to background ratio SERS probes for nitrofurazone metabolites ultrasensitive detection

In this work, an ultra-sensitive lateral flow immunoassay (LFIA) with SERS/colorimetric dual signal mode was constructed for the detection of nitrofurazone metabolites, an antibiotic prohibited in animal-origin foods. Au@4-MBN@AgNRs nano-sandwich structural signal tag integrates the unique advantages of high signal-to-background ratio and anti-matrix interference through geometric control of SERS tag and nanoengineering adjustment of chemical composition. Under the optimal conditions, the detection limits of nitrofurazone metabolites by SERS/colorimetric dual-mode LFIA were 20 pg/mL (colorimetric mode) and 0.08 pg/mL (SERS mode). Excitingly, the vLOD of the colorimetric signal improved by a factor of 100 compared to Au NPs-based LFIA. In this study, the proposed dual-mode LFIA was successfully applied to the on-site real-time detection of honey, milk powder, and chicken. It is anticipated that with low background interference and anti-matrix interference output signal, our proposed dual-mode strategy can pave an innovative pathway for the fabrication of a powerful biosensor.

Fortified Dual-Spectral Overlap with Enhanced Colorimetric/Fluorescence Dual-Response Immunochromatography for On-Site Bimodal-Type Gentamicin Monitoring

Immunochromatography (ICA) remains untapped toward enhanced sensitivity and applicability for fulfilling the nuts and bolts of on-site food safety surveillance. Herein, we report a fortified dual-spectral overlap with enhanced colorimetric/fluorescence dual-response ICA for on-site bimodal-type gentamicin (Gen) monitoring by employing polydopamine (PDA)-coated AuNPs (APDA) simultaneously serving as a colorimetric reporter and a fluorescence quencher. Availing of the enhanced colorimetric response that originated from the PDA layer, the resultant APDA exhibits less required antibody and immunoprobes in a single immunoassay, which facilitates improved antibody utilization efficiency and immuno-recognition in APDA-ICA. Further integrated with the advantageous features of fortified excitation and emission dual-spectral overlap for the Arg/ATT-AuNCs, this APDA-ICA with a "turn on/off" pattern achieves the visual limits of detection of 1.0 and 0.5 ng mL-1 for colorimetric and fluorescence patterns (25- and 50-fold lower than standard AuNPs-ICA). Moreover, the excellent self-calibration and satisfactory recovery of 79.03-118.04% were shown in the on-site visual colorimetric-fluorescence analysis for Gen in real environmental media (including real river water, an urban aquaculture water body, an aquatic product, and an animal byproduct). This work provides the feasibility of exploiting fortified dual-spectral overlap with an enhanced colorimetric/fluorescence dual response for safeguarding food safety and public health.

Precise Spectral Overlap-Based Donor-Acceptor Pair for a Sensitive Traffic Light-Typed Bimodal Multiplexed Lateral Flow Immunoassay

Bimodal-type multiplexed immunoassays with complementary mode-based correlation analysis are gaining increasing attention for enhancing the practicability of the lateral flow immunoassay (LFIA). Nonetheless, the restriction in visually indistinguishable multitargets induced by a single fluorescent color and difficulty in single acceptor ineffectual fluorescence quenching due to the various spectra of multiple different donors impede the further execution of colorimetric-fluorescence bimodal-type multiplexed LFIAs. Herein, the precise spectral overlap-based donor-acceptor pair construction strategy is proposed by regulating the size of the nanocore, coating it with an appropriate nanoshell, and selecting a suitable fluorescence donor with distinct colors. By in situ coating Prussian blue nanoparticles (PBNPs) on AuNPs with a tunable size and absorption spectrum, the resultant APNPs demonstrate efficient fluorescence quenching ability, higher colloidal stability, remarkable colorimetric intensity, and an enhanced antibody coupling efficiency, all of which facilitate highly sensitive bimodal-type LFIA analysis. Following integration with competitive-type immunoreaction, this precise spectral overlap-supported spatial separation traffic light-typed colorimetric-fluorescence dual-response assay (coined as the STCFD assay) with the limits of detection of 0.013 and 0.152 ng mL-1 for ractopamine and clenbuterol, respectively, was proposed. This work illustrates the superiority of the rational design of a precise spectral overlap-based donor-acceptor pair, hinting at the enormous potential of the STCFD assay in the point-of-care field.

A bifunctional core-shell gold@Prussian blue nanozyme enabling dual-readout microfluidic immunoassay of food allergic protein

Food allergy has posed a great threat for public health due to its rising prevalence worldwide, and thus sensitive and reliable food allergen monitoring methods is of great significance. In this study, we prepared a bifunctional core-shell gold@Prussian blue nanoparticles (Au@PBNP) nanozyme, which not only could serve as an alternative to natural peroxidase for colorimetric immunoassay, but also act as a unique Raman label in Raman-silent region (1800-2800 cm-1) for SERS analysis. By combining microfluidic device, smartphone, and portable Raman spectrometer, a new smartphone/SERS dual-readout microfluidic immunoassay platform was established for portable detection of food allergic protein (i.e., alpha-lactalbumin (α-LA)). The established method for detection of α-LA showed a LOD of 0.011 ng/mL in a liner range of 0.2-600 ng/mL. Furthermore, this method was also challenged in spiked food samples with good average recoveries, showing a great potential in practical applications.

Goat anti-mouse immunoglobulin as "crosslinker" assisted signal tracer assemble with intensive antibody utilization efficiency for sensitive paper-based strip nanobiosensors

Engineered collaborative biochemical techniques and regulated nanomaterials (NMs) offer extraordinary opportunities for improving the analysis performance of lateral flow immunoassay (LFIA). Herein, inspired by the ability of macromolecules (e.g., proteins) to assemble into new functional units and the remarkable optical performance of engineered regulated NMs, goat anti-mouse immunoglobulin (GAMI) serves as the "crosslinker" integrate with gold‑manganese oxide (Au-MnOx) to assemble the "signal tracers (STs)-crosslinker-antibody (mAb)" for elevating the mAb utilization efficiency. Notably, the "STs-crosslinker-mAb" assembly shows ~13.33-folds mAb utilization efficiency enhance, which perfectly response the challenge between limited sensitivity and sufficient signal intensity in competitive-type LFIA. The black color and rough structure of Au-MnOx offer higher colorimetric brightness (~2-folds than AuNPs) and enhanced mAb coupling efficiency (up to 92.47%), which further improves sensitivity under the premise of functional assembly to intensify the competitive immunoreaction. Additionally, the convenient synthesis conditions (~13 min at room temperature) even comparable to direct purchase commercial products indicate that using Au-MnOx undoubtedly increases the cost-effectiveness. Encouragingly, the Au-MnOx-GAMI-mAb based LFIA exhibited high sensitivity (LOD: 0.063 ng mL-1 for clenbuterol (CLE) monitoring) by elevating mAb utilization efficiency with the attendant enhancing immune competition response in a cost-effective manner, which provides an invigorating reference pathway in point-of-care immunoassay.

Recent advances in SERS-based immunochromatographic assay for pathogenic microorganism diagnosis: A review

Infectious diseases caused by bacteria, viruses, fungi, and other pathogenic microorganisms are among the most harmful public health problems in the world, causing tens of millions of deaths and incalculable economic losses every year. The establishment of rapid, simple, and highly sensitive diagnostic methods for pathogenic microorganisms is important for the prevention and control of infectious diseases, guidance of timely treatment, and the reduction of public safety risks. Lateral flow immunoassay (LFA) based on the colorimetric signal of colloidal gold is the most popular point-of-care testing technology at present, but it is limited by poor sensitivity and low throughput and hardly meets the needs of the highly sensitive screening of pathogenic microorganisms. In recent years, the combination of surface-enhanced Raman scattering (SERS) and LFA technology has developed into a novel analytical platform with high sensitivity and multiple detection capabilities and has shown great advantages in the detection of pathogenic microorganisms and infectious diseases. This review summarizes the working principle, design ideas, and application of the existing SERS-based LFA methods in pathogenic microorganism detection and further introduces the effect of new technologies such as Raman signal encoding, magnetic enrichment, novel membrane nanotags, and integrated Raman reading equipment on the performance of SERS-LFA. Finally, the main challenges and the future direction of development in this field of SERS-LFA are discussed.

SERS-active immunoassay kit for SARS-CoV‑2 mediated by the cooperative chemical and electromagnetic effects of MXene modified with gold nanowires

Surface-enhanced Raman scattering (SERS) technique with high sensitivity, reliable specificity, and rapid recognition ability exhibits attractive promise for the effective fast-monitoring of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, a novel SERS-active immunoassay kit for SARS-CoV-2 nucleocapsid (N) protein was prepared by in-situ growing gold (Au) nanowire forests (NFs) onto Ti3C2Tx, which was then modified onto polymethyl methacrylate (PMMA) matrix and encapsulated into kit. It was noted that the Au nanowires with fibrous structures which vertically anchored on Ti3C2Tx served as perfect channels to promote photo-induced charge transfer. The synergistic action of electromagnetic and chemical effects resulted in an enhancement factor (EF) of 1.27 × 107. Furthermore, the unreliable fluctuation of the enhanced signal was eliminated by using the intrinsic Raman signal of the flexible PMMA platform, achieving an improved correlation coefficient (R2) value from 0.950 to 0.990. Moreover, the as-designed immunoassay kit with both high sensitivity and remedied quantitative ability rendered by the Ti3C2Tx@Au NFs-PMMA composite exhibited a powerful performance in the practical detection of N-protein with concentration low to 5.0 × 10-8 mg/mL.

Biosensors based on potent miniprotein binder for sensitive testing of SARS-CoV‑2 variants of concern

The miniprotein binder TRI2-2 was employed as an antibody alternative to build a single antibody-coupled TRI2-2 based gold nanoparticle-based lateral flow immunoassay (AT-GLFIA) biosensor. The biosensor provides high specificity and affinity binding between TRI2-2 and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) spike antigen receptor binding domain (S-RBD). It also enables rapid testing of wild-type (WT), B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), P.1 (Gamma), and B.1.1.529 (Omicron) SARS-CoV-2 S-RBD and is at least ~ 16-fold more sensitive than conventional antibody pair-based GLFIA (AP-GLFIA). Besides, we developed a wireless micro-electrochemical assay (WMECA) biosensor based on the TRI2-2, which demonstrates an excellent VOCs testing capability at the pg mL-1 level. Overall, our results demonstrate that integrating miniprotein binders into conventional immunoassay systems is a promising design for improving the testing capabilities of such systems without hard-to-obtain antibody pair, complex reporter design, laborious signal amplification strategies, or specific instrumentation.

An Artificial Miniaturized Peroxidase for Signal Amplification in Lateral Flow Immunoassays

Signal amplification strategies are widely used for improving the sensitivity of lateral flow immunoassays (LFiAs). Herein, the artificial miniaturized peroxidase Fe(III)-MimochromeVI*a (FeMC6*a), immobilized on gold nanoparticles (AuNPs), is used as a strategy to obtain catalytic signal amplification in sandwich immunoassays on lateral flow strips. The assay scheme uses AuNPs decorated with the mini-peroxidase FeMC6*a and anti-human-IgG as a detection antibody (dAb), for the detection of human-IgG, as a model analyte. Recognition of the analyte by the capture and detection antibodies is first evidenced by the appearance of a red color in the test line (TL), due to the accumulation of AuNPs. Subsequent addition of 3,3',5,5'-tetramethylbenzidine (TMB) induces an increase of the test line color, due to the TMB being converted into an insoluble colored product, catalyzed by FeMC6*a. This work shows that FeMC6*a acts as an efficient catalyst in paper, increasing the sensitivity of an LFiA up to four times with respect to a conventional LFiA. Furthermore, FeMC6*a achieves lower limits of detection that are found in control experiments where it is replaced with horseradish peroxidase (HRP), its natural counterpart. This study represents a significant proof-of-concept for the development of more sensitive LFiAs, for different analytes, based on properly designed artificial metalloenzymes.

Nature-Derived Hollow Micron-Tubular Signal Tracers Conquering the Size Limitations for Multimodal Immunochromatographic Detection of Antibiotics

Developing signal tracers (STAs) with large size, multifunctionality, and high retention bioaffinity is believed to be a potential solution for achieving high-performance immunochromatographic assays (ICAs). However, the size limitations of STAs on strips are always a challenge because of the serious steric hindrance. Here, based on metal-quinone coordination and further metal etching, hollow micron-tubular STAs formed by natural alizarin and Fe3+ ions (named ALIFe) are produced to break through size limitations, provide more active sites, and achieve three-mode ICAs (ALIFe STAs-ICAs). Thanks to the special tubular morphology, ALIFe can successfully pass through the strip and provide an ideal signal intensity within 7 min at low mAb and probe dosages to achieve stable ICA analysis. Importantly, ALIFe shows excellent antibody enrichment and bioaffinity retention capability. With a proof-of-concept for streptomycin, the ALIFe STAs-ICAs showed the limit of detection (LOD) at 0.39 ng mL-1 for colorimetric mode, 0.32 ng mL-1 for catalytic mode, and 0.016 ng mL-1 for photothermal mode with total recoveries ranging from 80.46 to 121.59% in mike and honey samples. We anticipate that our study will help expand the ideas for the design of high-performance STAs with large size and broaden the practical application of ICA.

Engineered Collaborative Size Regulation and Shape Engineering of Tremella-Like Au-MnOx for Highly Sensitive Bimodal-Type Lateral Flow Immunoassays

Engineered collaborative size regulation and shape engineering of multi-functional nanomaterials (NPs) offer extraordinary opportunities for improving the analysis performance. It is anticipated to address the difficulty in distinguishing color changes caused by subtle variations in target concentrations, thereby facilitating the highly sensitive analysis of lateral flow immunoassays (LFIAs). Herein, tremella-like gold-manganese oxide (Au-MnOx ) nanoparticles with precise MnCl2 regulation are synthesized as immuno signal tracers via a facile one-step redox reaction in alkaline condition at ambient temperature. Avail of the tunable elemental composition and anisotropy in morphology, black-colored tremella-like Au-MnOx exhibits superb colorimetric signal brightness, enhanced antibody coupling efficiency, marvelous photothermal performance, and unrestricted immunological recognition affinity, all of which facilitate highly sensitive multi-signal transduction patterns. In conjunction with the handheld thermal reader device, a bimodal-type LFIA that combines size-regulation- and shape-engineering-mediated colorimetric-photothermal dual-response assay (coined as the SSCPD assay) with a limit of detection of 0.012 ng mL-1 for ractopamine (RAC) monitoring is achieved by integrating Au-MnOx with the competitive-type immunoreaction. This work illustrates the effectiveness of this strategy for establishing high-performance sensing, and the SSCPD assay may be extended to a wide spectrum of future point-of-care (POC) diagnostic applications.

Supramolecular recognition enhanced electrochemical sensing: β-cyclodextrin and Pd nanoparticle co-decorated 3D reduced graphene oxide nanocomposite-modified glassy carbon electrode for the quantification of ractopamine

Ractopamine (RAC) is universally known for improving lean meat percentage in livestock and thus is widely introduced as a feed additive. However, it is difficult to eliminate the RAC residue in animal tissues from the biological system and will inevitably harm human health. Hence, detecting RAC molecules in biological samples is extremely significant. Herein, a novel strategy of supramolecular recognition-enhanced electrochemical sensing is presented. This platform was constructed by coupling β-cyclodextrin (β-CD) with palladium nanoparticles (Pd NPs)-functionalized three-dimensional reduced graphene oxide (3D-rGO) to form a nanocomposite (3D-rGO/Pd/β-CD), which was further used to modify a glassy carbon electrode (GCE) for RAC detection. Benefiting from the attractive electrical conductivity and catalytic activity of 3D-rGO/Pd, as well as the unique small-molecule-recognition ability of β-CD demonstrated by ¹H NMR spectrum, which revealed the 1 : 2 binding mode of RAC with β-CD, increased peak current signals of RAC were observed in the cyclic voltammetry (CV) test. Under optimized conditions, the wide linear concentration range spanned 1-95 μM, along with a relatively low detection limit of 0.12 μM (S/N = 3), as evidenced by the differential pulse voltammetry (DPV) approach. The platform also exhibited satisfactory stability and fine reproducibility, as well as high selectivity and good anti-interference capability. Moreover, this as-obtained sensor was efficiently applied in pork samples with a high recovery rate (96.44-103.99%), which provides a promising view of its electrochemical biosensing ability in practical applications.

Biomineralization-inspired artificial clickase for portable click SERS immunoassay of Salmonella enterica serovar Paratyphi B in foods

Inspired by a biomineralization behavior, we prepared a nanoflower-like artificial clickase (namely LCN clickase) for portable and sensitive click SERS immunoassay of foodborne bacterial pathogen. Encouraged by its high click catalytic activity to trigger Cu(I)-catalyzed azide-alkyne cycloaddition reaction, LCN clickase was successfully used for establishing a novel click SERS immunoassay by combining the clickase-mediated SERS signal variation at Raman-silent region. The developed method not only effectively eliminated the interferences between Raman reporter and biological species, but also reduced the complex sample matrix interference. Compared with traditional CuAAC-based immunoassays, the established method avoided the superfluous dissolution process of nanocatalysts and eliminated the requirement of reducing agent during detection, thereby shortening detection time and improving detection reliability. Impressively, the proposed method showed high selectivity and sensitivity for detection of Salmonella enterica serovar Paratyphi B with a low LOD of 20 CFU/mL, exhibiting a great potential in detection of foodborne bacterial pathogen in food samples.

Design, Fabrication, and Applications of SERS Substrates for Food Safety Detection: Review

Sustainable and safe food is an important issue worldwide, and it depends on cost-effective analysis tools with good sensitivity and reality. However, traditional standard chemical methods of food safety detection, such as high-performance liquid chromatography (HPLC), gas chromatography (GC), and tandem mass spectrometry (MS), have the disadvantages of high cost and long testing time. Those disadvantages have prevented people from obtaining sufficient risk information to confirm the safety of their products. In addition, food safety testing, such as the bioassay method, often results in false positives or false negatives due to little rigor preprocessing of samples. So far, food safety analysis currently relies on the enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), HPLC, GC, UV-visible spectrophotometry, and MS, all of which require significant time to train qualified food safety testing laboratory operators. These factors have hindered the development of rapid food safety monitoring systems, especially in remote areas or areas with a relative lack of testing resources. Surface-enhanced Raman spectroscopy (SERS) has emerged as one of the tools of choice for food safety testing that can overcome these dilemmas over the past decades. SERS offers advantages over chromatographic mass spectrometry analysis due to its portability, non-destructive nature, and lower cost implications. However, as it currently stands, Raman spectroscopy is a supplemental tool in chemical analysis, reinforcing and enhancing the completeness and coverage of the food safety analysis system. SERS combines portability with non-destructive and cheaper detection costs to gain an advantage over chromatographic mass spectrometry analysis. SERS has encountered many challenges in moving toward regulatory applications in food safety, such as quantitative accuracy, poor reproducibility, and instability of large molecule detection. As a result, the reality of SERS, as a screening tool for regulatory announcements worldwide, is still uncommon. In this review article, we have compiled the current designs and fabrications of SERS substrates for food safety detection to unify all the requirements and the opportunities to overcome these challenges. This review is expected to improve the interest in the sensing field of SERS and facilitate the SERS applications in food safety detection in the future.

Carbon black as a colorimetric label for an immunochromatographic test strip for severe fever with thrombocytopenia syndrome virus detection

To combat the ongoing threat posed by severe fever with thrombocytopenia syndrome virus (SFTSV), especially in underserved areas, there is an urgent need for an affordable and reliable point-of-care diagnostic tool. This study presents a carbon black-based immunochromatographic test strip (CB-ICTS) for the detection of SFTSV, which is both quick and easy to operate. The study optimized the specific steps for carbon black-labeled antibodies, as well as the amount of carbon black and anti-SFTSV antibody used. Under optimal experimental conditions, the linear range and limit of detection of the CB-ICTS were evaluated using different concentrations of SFTSV standard samples. The detection range of the CB-ICTS for SFTSV was found to be 0.1-1000 ng mL^-1, with a limit of detection of 100 pg mL^-1. The precision and accuracy of the CB-ICTS were assessed by examining spiked healthy human serum samples, which displayed recoveries ranging from 91.58 to 105.4% with a coefficient of variation of less than 11%. This work evaluated the specificity of the CB-ICTS using various biomarkers (CA125, AFP, CA199, CEA, and HCG) and demonstrated that the CB-ICTS is highly specific for detecting SFTSV, suggesting its potential for the early diagnosis of SFTSV. In addition, the study evaluated the CB-ICTS in serum samples from patients with SFTSV, and the results were highly consistent with those detected by the polymerase chain reaction (PCR) method. Overall, this study demonstrates the feasibility and effectiveness of using the CB-ICTS as a reliable point-of-care diagnostic tool for the early detection of SFTSV.