Sensitive Immunoassay Research Articles

Development and validation of a sensitive sandwich ELISA against human PINK1

ABSTRACT The ubiquitin kinase and ligase PINK1 and PRKN together label damaged mitochondria for their elimination in lysosomes by selective autophagy (mitophagy). This cytoprotective quality control pathway is genetically linked to familial Parkinson disease but is also altered during aging and in other neurodegenerative disorders. However, the molecular mechanisms of these mitophagy changes remain uncertain. In healthy mitochondria, PINK1 protein is continuously imported, cleaved, and degraded, but swiftly accumulates on damaged mitochondria, where it triggers the activation of the mitophagy pathway by phosphorylating its substrates ubiquitin and PRKN. Levels of PINK1 protein can therefore be used as a proxy for mitochondrial damage and mitophagy initiation. However, validated methodologies to sensitively detect and quantify PINK1 protein are currently not available. Here, we describe the development and thorough validation of a novel immunoassay to measure human PINK1 on the Meso Scale Discovery platform. The final assay showed excellent linearity, parallelism, and sensitivity. Even in the absence of mitochondrial stress (i.e. at basal conditions), when PINK1 protein is usually not detectable by immunoblotting, significant differences were obtained when comparing samples from patient fibroblasts or differentiated neurons with and without PINK1 expression. Of note, PINK1 protein levels were found increased in human postmortem brain with normal aging, but not in brains with Alzheimer disease, suggesting that indeed different molecular mechanisms are at play. In summary, we have developed a novel sensitive PINK1 immunoassay that will complement other efforts to decipher the roles and biomarker potential of the PINK1-PRKN mitophagy pathway in the physiological and pathological context. Abbreviations: AD: Alzheimer disease; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; ECL: electrochemiluminescence; ELISA: enzyme-linked immunosorbent assay; iPSC: induced pluripotent stem cell; KO: knockout; LLOQ: lower limit of quantification; MSD: Meso Scale Discovery; PD: Parkinson disease; p-S65-Ub: serine-65 phosphorylated ubiquitin; Ub: ubiquitin; ULOQ: upper limit of quantification; WT: wild-type.

Evaluation of Immunoassay Performance for the Detection of Opioids in Urine.

Immunoassay drug screens provide rapid analysis of urine for the presence of therapeutics and drugs of abuse. Compared to definitive (confirmatory) methods, immunoassays are prone to false-positive and -negative results. Laboratories generally rely on manufacturers' claims regarding method sensitivity and specificity; few have the resources to independently verify performance. In this study, we review the performance of our opioid immunoassay drug screens in comparison to a definitive method. Results of 859 urine samples tested via opioid immunoassay screens for buprenorphine, fentanyl, methadone metabolite (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine; EDDP), opiates, and oxycodone were compared to definitive results obtained via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The data examined here included multiple samples from individual patients. Our quantitative LC-MS/MS method includes 19 opioid compounds (parent drugs plus metabolites). Immunoassay sensitivity and specificity ranged from 96% to 100% and 84% to 99%, respectively. The sensitivity and specificity of these screens were similar to manufacturers' claims with some exceptions. The opiates immunoassay had poor performance when limiting the comparison to its target compound, morphine, but improved when including all compounds listed in the manufacturer's instructions for use (IFU). While demonstrating good sensitivity, the buprenorphine immunoassay demonstrated lower specificity than stated in the IFU. The opioid immunoassay screens in use at our facility compared favorably to a definitive LC-MS/MS method. The urine fentanyl screen had the lowest sensitivity (96%) and had a specificity of 97%. The urine buprenorphine assay was the least specific (84%) and had a sensitivity of 99%.

A Highly Sensitive Immunoassay to Enable Quantification of a Nanobody-Based Imaging Agent in Human Serum.

Immuno-positron emission tomography (i-PET) is a non-invasive imaging technique that combines the specificity of monoclonal antibodies with the sensitivity of positron emission tomography to visualize and quantify the distribution of target antigens in vivo, providing detailed spatial information about the presence and localization of specific biomarkers. Due to the crucial role that cytotoxic T cells play in antitumor responses, a new tracer consisting of a humanized anti-CD8 nanobody labeled with fluorine-18 was developed to inform immuno-oncology treatments and support medical decision-making. Nanobodies are single-domain antibodies with low molecular weight and fast peripheral blood clearance, both of which are advantageous properties for same-day imaging. However, these unique characteristics pose bioanalytical challenges when developing clinical pharmacokinetic (PK) assays, including the need for high assay sensitivity. This manuscript focuses on overcoming bioanalytical challenges related to sensitivity and matrix interference during the development of a method to quantify this novel anti-CD8 nanobody tracer in human serum. Out of the three immunoassay platforms evaluated (ELISA, SMCxPRO™ and Gyrolab®), a Gyrolab method was ultimately selected due to its superior sensitivity, equal detectability of both conjugated and unconjugated forms of the nanobody and its ability to minimize matrix interference. By selecting the right assay format, along with the appropriate critical reagents for capture and detection, matrix interference was diminished. This novel PK method was successfully qualified demonstrating acceptable performance across all parameters. The acquired bioanalytical insights gained could be applied to nanobody-derived conjugates or other modalities that require high sensitivity in the clinical settings.

Ferrous Tungstate Nanomaterials with Excellent Enzyme-Mimicking Activity to Enhance Lateral Flow Immunoassay Sensitivity.

Lateral flow immunochromatography (LFIA) with gold nanoparticles (AuNPs) is widely used in the biomedical field as a rapid and simple in vitro detection technique. However, the conventional AuNP-LFIA has limitations in sensitivity and detection range. In this study, nonprecious metal iron-based bimetallic FeWO4 nanomaterials with convenient and excellent enzyme-mimetic catalytic activities were synthesized by a one-pot hydrothermal method. Here, FeWO4 nanomaterials were combined with C-reactive protein (CRP) detection antibodies to form a novel signal-enhancing probe for the analysis of CRP. The probe further achieves significant signal amplification by catalyzing the oxidation reaction of 3-amino-9-ethylcarbazole in the LFIA assay, thereby improving the sensitivity and accuracy of the assay. The application of FeWO4-based LFIA improved the limit of detection of CRP to 19.38 ng/mL after catalytic amplification, which is approximately 30-fold lower than that of the conventional AuNP-LFIA method. In addition, the method demonstrated good stability and reproducibility, providing a promising and prospective strategy for the early diagnosis of inflammatory diseases.

Individual and combined effects of dietary vitamin intake on cognitive function in elderly adults: the potential mediating role of serum neurofilament light chain levels

BackgroundVitamins are essential micronutrients for the prevention and treatment of neurodegenerative diseases. The objectives of the present study were to evaluate the association between dietary vitamin intake and cognitive function in elderly adults and to explore the potential impact of serum neurofilament light chain (NfL) concentration.MethodsData from 468 elderly individuals, including information on the dietary consumption of 10 vitamins, were used. Cognitive performance was assessed according to a composite Z-score of the Animal Fluency Test (AFT), Consortium to Establish a Registry for Alzheimer’s Disease (CERAD), and Digit Symbol Substitution Test (DSST). Serum NfL levels were measured using a highly sensitive immunoassay. Bayesian kernel machine regression (BKMR) models were used to estimate the combined effects of vitamin mixtures on cognitive function.ResultsIn both single- and multiple-vitamin models, individuals with a higher intake of dietary vitamin K exhibited greater global cognitive function, compared to those with a lower vitamin intake. BKMR revealed positive associations between vitamin mixtures and global cognitive function, AFT Z-scores, and DSST Z-scores. Individuals in the third vitamin K intake tertile exhibited lower serum NfL levels than those in the first tertile (regression coefficient, β = −0.16 [95% confidence interval −0.29 to −0.02]; p = 0.023). Serum NfL levels mediated the association between higher vitamin K intake and global cognitive function (8.73%).ConclusionVitamin mixtures were positively associated with global cognitive function in elderly participants. The association between vitamin K intake and cognitive function may be mediated by serum NfL concentration.

Exploration of vitamin D hydroxy metabolites C3 epimers in patients with cardiovascular disease: an observational study.

Roughly 90% of the Polish population experiences vitamin D deficiency. The 3-epi-25(OH)D2 and 3-epi-25(OH)D3 are stereoisomers of 25(OH)D2 and 25(OH)D3, and they can inadvertently be included in measurements of 25(OH)D levels, potentially leading to its overestimating. We aimed to measure 25(OH)D2 and 25(OH)D3, their epimers 3-epi-25(OH)D2 and 3-epi-25(OH)D3, and biologically active 1,25(OH)2D3 in patients with cardiovascular disease and healthy volunteers. We enrolled 27 adult patients with cardiovascular disease (64 ± 15 years) and 35 healthy volunteers (36.37 ± 12.29 years). We used a validated ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS) method to measure 25(OH)D2/3 concentrations and their epimers. Plasma concentrations of 1α,25(OH)2D3 were determined by sensitive and quantitative enzyme immunoassay following intra- and inter-day validation. Vitamin D insufficiency was observed in approximately 52% of the patients and 37% of healthy volunteers. Comparable levels of 25(OH)D3 and 25(OH)D2 were seen in both groups. The observed levels of the epimeric form 3-epi-25(OH)D3 appeared approximately 1.7 times higher in healthy volunteers, accounting for 9% misclassified according to vitamin D status. Also, patients had lower concentrations of 1,25(OH)2D3, and their 3-epi-25(OH)D2 levels were below the detection limit (2 ng/mL). In all studied subjects, 25(OH)D3 was negatively correlated with % 3-epi-25(OH)D3 (R=-0.758; P<0.001), and 3-epi-25(OH)D2 was negatively correlated with % 3-epi-25(OH)D2 (R = -0.842; P = 0.002). While the mechanism of how vitamin D epimeric forms influence diseases remains unclear, we recommend maintaining 25(OH)D3 levels above 20 ng/mL.

Highly Sensitive Digital and Analog Immunoassay Based on Submicron Magnetic Beads and Fluorescent Microspheres.

The detection of disease-related protein biomarkers plays a crucial role in the early diagnosis, treatment, and monitoring of diseases. The concentrations of protein biomarkers can vary significantly in different diseases or stages of the same disease. However, most of the existing analytical methods cannot simultaneously meet the requirements of high sensitivity and a wide dynamic range. Herein, we developed a digital and analog immunoassay method based on submicron magnetic beads and fluorescent microspheres. The digital analysis achieves a limit of detection as low as 46 fg/mL (1.8 fM) for IL-6, and the analog analysis has a wide dynamic range spanning from 0.2 pg/mL to 10 ng/mL. Furthermore, the analog analysis can be used to quickly and roughly assess higher concentration proteins via visual detection, and the practical application potential of this method was verified by the detection of alpha-fetoprotein in serum samples from 12 healthy individuals and hepatocellular carcinoma patients. The established method does not involve the use of enzymes or costly instruments, which greatly simplifies the experimental steps, shortens the experimental time, and reduces the experimental cost. In view of those advantages, the proposed method has great application prospects in point-of-care applications.

Intra-Mesopore Immunoassay Based on Core-Shell Structured Magnetic Hierarchically Porous ZIFs.

It is crucial yet challenging to sensitively quantify low-abundance biomarkers in blood for early screening and diagnosis of various diseases. Herein, an analytical model of intra-mesopore immunoassay (IMIA) was proposed, which was competent to examine various biomarkers at the femtomolar level. The success is rooted in the design of an innovative superparamagnetic core-shell structure with Fe3O4 nanoparticles (NPs) at the core and hierarchically porous zeolitic imidazolate frameworks as a shell (Fe3O4@HPZIF-8), achieved through a soft-template directed self-assembly coupled with confinement growth mechanism. Such a unique configuration conceptualized IMIA where the HPZIF-8 shell served as a solid carrier to cover capture antibodies while the Fe3O4 core assisted its rapid separation. The large pore channels not only provided a stable microenvironment to maintain the recognition ability of captured antibodies but also enhanced their coating density, thus promoting the probability of capturing and binding target antigens, significantly improving immunoassay (IA) sensitivity. The practical clinic IA for cTnI (Cardiac Troponin I, biomarker of acute myocardial infarction (AMI)) in human serums was exemplified. The developed IMIA could accurately quantify slight fluctuations in cTnI concentrations in the serums of AMI patients at different stages after symptom onset with more than 100-fold enhancement of limit of detection (LOD) in comparison to conventional plate-based enzyme-linked immunosorbent assay (ELISA). Such high sensitivity of IMIA makes it a powerful tool for the accurate diagnosis of different diseases by altering the type of primary capture antibody.

Development of highly sensitive lateral flow immunoassay using PdNPs for detection of Plasmodium species.

A lateral flow immunoassay (LFIA) employing palladium nanoparticles (PdNPs) labelled with antibodies has been innovatively designed for the precise detection of Plasmodium falciparum pLDH and HRPII antigen. This study focuses on development of LFIA based on PdNPs detection system to substantially enhance the visual detectability (vLOD), achieving an impressive 12 parasites/microliter (p/µl) vLOD in comparison with conventional system represented 50 p/µl vLOD. The research introduces a novel amplification system that not only heightens the sensitivity of LFIA but also maintains intense coloration. This novel system relies on direct detection of the malaria pLDH and HRPII antigen. In this innovative assay, HRPII antigen interacts with PdNP-conjugated Anti-HRPII detector antibodies, forming an immune complex with Anti-HRPII capture antibodies. The detection limit for HRPII antigen was found to be 8 times higher than that of conventional systems. Moreover, the novel approach for synthesis of PdNPs and their conjugation with antibodies makes this system robust and universally applicable and also extends its potential use to detect various other compounds, including antigens or antibodies from different diseases. This sensitive LFIA detection system presents itself as an efficient screening tool for medical monitoring and point-of-care (POC) settings, offering promising prospects for enhancing disease diagnosis and surveillance.

Non-competitive immunoassay for zearalenone based on phage display developed recombinant antibody and anti-immunocomplex peptide.

Zearalenone (ZEN) is a widely distributed mycotoxin with potent estrogenic activity. Detecting ZEN is crucial for assessing its potential health risks. This study developed a highly sensitive non-competitive magnetic phage anti-immunocomplex immunoassay (Nc-MPHAIA) for ZEN detection, utilizing the anti-ZEN single-chain variable fragment (ScFv) and anti-immunocomplex peptide (AIcP), both of which were screened using phage display technology. The method exhibited a limit of detection of 0.005ng/mL, which was 112 times lower than that of the conventional competitive immunoassay using the same ScFv and the chemosynthetic antigen ZEN-OVA. Validation studies demonstrated excellent recovery rates in spiked corn samples (intra-assay: 84.04-109.95%; inter-assay: 89.70-99.59%). Additionally, the Nc-MPHAIA results for ZEN in natural samples were consistent with those obtained via high-performance liquid chromatography, which demonstrated good reliability of the established assay.

Development of sensitive and rapid immunoassays for Moniliformin (MON) detection based on nanomaterials labeled monoclonal antibodies.

Moniliformin (MON) is a toxic secondary metabolite from Fusarium species. The natural contamination of MON in cereals and cereal by-products, poses a risk of exposure to MON. However, so far, no immunoassay method has been reported to detect MON in field samples. In this study, anti-MON monoclonal antibody (mAb) with high affinity (1×108) and isotype of IgG1 was subjected to establish indirect competitive ELISA (ic-ELISA) and immunochromatographic test strips (ICTS). The optimized ic-ELISA resulted in the lowest detection limit (LOD) of 1.55μg/mL. The LOD value for gold nanoparticles (AuNP) -based test strip was 0.83μg/mL. The multi branched gold nano-flower particles (AuNFs) reported higher sensitivity with LOD of 0.38μg/mL. Moreover, the developed test strips exhibited a high specificity without cross-reactivity to related competitive toxins. In conclusion, immunoassay methods were successfully developed to detect MON in field samples with a short detection time to ensure food security.

Fluorescence Polarization Immunoassay for Rapid, Sensitive Detection of the Herbicide 2,4-Dichlorophenoxyacetic Acid in Juice and Water Samples.

2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the popular herbicides that is widely used in agriculture and can be found in food and water. A rapid and sensitive fluorescence polarization immunoassay (FPIA) was proposed for the detection of 2,4-D in juice and water. New tracers, 2,4-D-buthylenediamin fluoresceinthiocarbamyl (2,4-D-BDF) and 2,4-D-glycine aminofluorescein (2,4-D-GAF), were obtained and characterized. Monoclonal antibodies (MAb) obtained against 2,4-D were used as a recognition reagent. The kinetics of the interaction of MAb and tracers were studied, and the kinetic parameters of their binding were calculated. High specificity of binding of tracers and MAb was shown. In this work, an approach was elaborated on to reduce the detection limit of 2,4-D by the FPIA method by changing the volume of the studied sample. The optimized FPIA in a competitive format was characterized by the LODs of 2,4-D 8 and 0.4 ng/mL and the working ranges 30-3000 ng/mL and 3-300 ng/mL for juice and water, respectively. The entire test cycle (from sample receipt to evaluation of the analysis results) took only 20 min. The test for the recovery of 2,4-D in juice and water gave values from 95 to 120%, which demonstrated the reliability of the herbicide determination in real samples.

Quantitative and rapid lateral flow immunoassay for cardiac troponin I using dendritic mesoporous silica nanoparticles and gold nanoparticles.

Acute myocardial infarction (AMI) is considered to be one of the predominant causes of human death; therefore, a rapid and accurate diagnostic method for AMI is urgently required. In this work, a highly sensitive lateral flow immunoassay (LFIA) platform was designed and fabricated for the quantitative determination of cardiac troponin I (cTnI) using a scanner, a smartphone and a colloidal gold immunoassay analyzer. To overcome the limitation of low sensitivity of traditional colloidal gold-based LFIA, three-dimensionally assembled gold nanoparticles (AuNPs) within a dendritic mesoporous silica nanoparticle (DMSN) scaffold were fabricated as signal labels. The assembly structure greatly enhanced the light extinction ability of a single label for signal amplification. The DMSNs@Au-based LFIA strips exhibited excellent detection performance including a high sensitivity (LOD = 70 pg mL-1) and wide linear range (0.5-40 ng mL-1) and precision with good specificity. The successful determination of cTnI by the test strips provides the ability to diagnose AMI at an early stage and expands the diagnostic window of AMI, while also having advantages such as low cost and user-friendliness. Therefore, we believe that the test strips fabricated in this work have great potential to be applied for practical clinical applications for the early and accurate diagnosis of AMI.

Sensitive lateral flow immunoassay based on integrated green pretreatment for detection of three mycotoxins in maize and wheat

Sensitive lateral flow immunoassay based on integrated green pretreatment for detection of three mycotoxins in maize and wheat

Fluorescent Particles Based on Aggregation-Induced Emission for Optical Diagnostics of the Central Nervous System.

In 2001, Tang's team discovered a unique type of luminogens with substantial enhanced fluorescence upon aggregation and introduced the concept of "aggregation-induced emission (AIE)". Unlike conventional fluorescent materials, AIE luminogens (AIEgens) emit weak or no fluorescence in solution but become highly fluorescent in aggregated or solid states, due to a mechanism known as restriction of intramolecular motions (RIM). Initially considered a purely inorganic chemical phenomenon, AIE was later applied in biomedicine to improve the sensitivity of immunoassays. Subsequently, AIE has been extensively explored in various biomedical applications, especially in cell imaging. Early studies achieved nonspecific cell imaging using nontargeted AIEgens, and later, specific cellular imaging was realized through the design of targeted AIEgens. These advancements have enabled the visualization of various biomacromolecules and intracellular organelles, providing valuable insights into cellular microenvironments and statuses. Neurological disorders affect over 3 billion people worldwide, highlighting the urgent need for advanced diagnostic and therapeutic tools. AIEgens offer promising opportunities for imaging the central nervous system (CNS), including nerve cells, neural tissues, and blood vessels. This review focuses on the application of AIEgens in CNS imaging, exploring their roles in the diagnosis of various neurological diseases. We will discuss the evolution and conclude with an outlook on the future challenges and opportunities for AIEgens in clinical diagnostics and therapeutics of CNS disorders.

Supramolecular self-assembly of high-loaded horseradish peroxidase and biorecognized antibody into Au/polydopamine nanocomposites for sensitive immunoassay of E. coli O157:H7 in milk.

It is an urgent need of rapid and sensitive method for detection of Escherichia coli O157:H7 (E. coli O157:H7), a class of hazardous foodborne pathogens in food safety. The traditional enzyme-linked immunosorbent assay (ELISA), a dominant rapid detection technic, takes disadvantages of low test sensitivity due to the insufficient enzyme loading capacity. In this study, we successfully synthesized the self-assembled Au/polydopamine (PDA)/HRP nanocomposites with the high enzyme loading on the outer surface and in the inner space. The high catalytic activity of Au/PDA/HRP was maintained by virtue of its hyperbranched flexible structure. For E. coli O157:H7 detection in milk samples, the proposed immunoassay achieved a visual cut-off value of 103 cfu mL-1 and a low limit of detection (LOD) of 2.8 × 102 cfu mL-1, 33 and 46 times more sensitive than the traditional ELISA, respectively. The tremendous advantages of high sensitivity, excellent specificity and adequate recovery make it promising for sensitively monitoring various kinds of pathogenic bacteria in food safety.

Embracing Nature's Wisdom: Liposome-Mediated Amplification of Electrochemiluminescence for the Sensitive and Selective Immunoassay of Serum Amyloid A.

Serum amyloid A (SAA) is a key biomarker for diagnosing inflammatory responses in diseases like influenza and COVID-19. An electrochemiluminescence (ECL) biosensor has been constructed for signal enhancement in SAA detection by encapsulating 4,4',4″,4‴-(1,3,6,8-pyrenetetrayl) tetrakis-benzoic acid (TBAPy) into liposomes. Such biomimetic encapsulation shields the biologically important membrane to avoid aggregation of TBAPy and prevents quenching. It would enhance the ECL signal's stability and intensity, resulting in a 5-fold signal increase with a relative standard deviation (RSD) of 1.71%. The biosensor has shown very good specificity and sensitivity toward SAA detection. The estimated detection limit is 0.188 pg/mL. This innovative approach integrates biomimicry with ECL technology and represents a leap in developing the next generation of diagnostic tools with superior sensitivity and specificity.

Highly Sensitive Lateral Flow Immunodetection of the Insecticide Imidacloprid in Fruits and Berries Reached by Indirect Antibody-Label Coupling.

A highly sensitive lateral flow immunoassay (LFIA) for imidacloprid, a widely used neonicotinoid insecticide, has been developed. The LFIA realizes the indirect coupling of anti-imidacloprid antibodies and gold nanoparticle (GNP) labels directly in the course of the assay. For this purpose, the common GNPs conjugate with anti-imidacloprid antibodies and are changed into a combination of non-modified, anti-imidacloprid antibodies, and the GNPs conjugate with anti-species antibodies. The given approach provides the possibility of selecting independent concentrations of GNPs and anti-imidacloprid antibodies to obtain the influence of minimal imidacloprid concentrations in the samples on the formation of detected, labeled immune complexes. A comparative study of imidacloprid LFIAs with common and indirect antibody-label coupling was implemented. The second variant reduced the limit of detection (LOD) of imidacloprid 20 times, reaching 0.2 ng/mL and 0.002 ng/mL for visual and instrumental detection, respectively, thus surpassing the existing LFIAs for imidacloprid. The developed highly sensitive LFIA was tested for imidacloprid detection in freshly squeezed fruits and berries without any additional sample preparation. The imidacloprids revealed were in the range of 75-97% for grape, 75-85% for orange, and 86-97% for apple samples. The time of the testing was 15 min.

Detection of TNF-α using the established ab-MPs-CLIA

Tumor necrosis factor alpha (TNF-α) is a key cytokine in inflammation and immune responses, making its rapid and accurate detection essential for disease diagnosis and management. In this study, we developed a highly sensitive chemiluminescence immunoassay (CLIA) using antibody-coated magnetic particles (Ab-MPs-CLIA) for TNF-α detection. From nine candidate antibodies, we identified an optimal pair through epitope competition and affinity assessments, significantly improving assay performance. The Ab-MPs-CLIA achieved a detection limit of 0.25 pg/mL, 6.8 times more sensitive than Siemens commercial kits, with a broad linear range of 9.2–1077 pg/mL. The method demonstrated excellent stability, both under accelerated conditions at 37 °C for 7 days and long-term storage at 4 °C for 12 months. It showed no cross-reactivity with common interfering substances in human serum, ensuring high specificity. Notably, the entire process, from sample preparation to result, takes just 25 min, compared to 3–4 h for both ELISA and RIA, and CLIA typically offers 10–100 times higher sensitivity than these methods. These advantages make the Ab-MPs-CLIA an ideal option for clinical laboratories, providing superior sensitivity, specificity, broader dynamic range, and greater operational efficiency than existing TNF-α detection technologies.

Selective surface passivation of gold nanoparticles: A strategy for enhanced sensitivity in lateral flow immunoassay

Selective surface passivation of gold nanoparticles: A strategy for enhanced sensitivity in lateral flow immunoassay