A novel multiplex lateral flow assay (mLFA) was developed using multicolor fluorescent hollow ZrO2@CdTe nanoparticles for the simultaneous, sensitive, and specific detection of two key cardiac biomarkers: C-reactive protein (CRP) and troponin T (cTnT). The assay leveraged the tunable fluorescence properties of ZrO2@CdTe nanoparticles, which were synthesized via a hydrothermal method with reaction times of 30, 40, and 50 minutes to yield green, yellow, and red-emitting particles respectively. These nanoparticles exhibited strong photostability, high quantum yield, and excellent resistance to environmental degradation due to the protective hollow zirconia shell. After functionalization with thiol groups, CdTe quantum dots were successfully anchored on the surface, resulting in stable and highly fluorescent probes.
In the mLFA design, red-colored ZrO2@CdTe nanoparticles were conjugated with CRP-specific detection antibodies, while green-colored nanoparticles were linked to cTnT-specific antibodies. The assay strip consisted of a sample pad, nitrocellulose membrane with two test lines (T1 for CRP, T2 for cTnT), and a control line (C) coated with goat anti-mouse IgG.SYNM Antibody manufacturer Upon application of a sample containing both biomarkers, antigen-antibody complexes formed and migrated along the strip via capillary action. At the T1 line, CRP was captured by immobilized capture antibodies, leading to accumulation of red fluorescent nanoparticles. Similarly, cTnT was detected at the T2 line through green fluorescence. The control line confirmed proper fluid flow and reagent integrity.
Visual inspection under a 365-nm UV lamp revealed distinct, non-overlapping signals: red fluorescence indicated CRP presence, green fluorescence signaled cTnT, and the control line confirmed assay validity. The visual limits of detection were determined to be 10 g/L for CRP and 0.1 mg/L for cTnT, demonstrating high sensitivity. Cross-reactivity tests showed no significant signal interference between the two analytes, confirming excellent specificity even at varying concentrations. For instance, when CRP levels varied from 100 to 0 g/L, the green signal on the cTnT line remained unchanged, and vice versa, indicating no cross-binding.
The performance of the mLFA was further validated using complex biological matrices such as fetal bovine serum (FBS), where the results closely matched those obtained in buffer solutions, highlighting its robustness against matrix effects. Optimization studies identified 20 minutes as the optimal response time for complete signal development, consistent across all samples. Probe concentration was also optimized, with 15 μL found to yield the strongest and most reproducible signals without background noise.
Compared to existing methods—including colloidal gold-based LFAs, ELISA, and other nanoparticle-labeled assays—the ZrO2@CdTe-based mLFA offers superior sensitivity, multiplexing capability, and ease of visual interpretation.MRPL44 Antibody Biological Activity Its ability to detect two critical cardiac markers simultaneously within a single test strip significantly enhances diagnostic efficiency, particularly in emergency settings where rapid decision-making is crucial.PMID:35252414 Moreover, the use of multicolor fluorescent labels eliminates the need for expensive instrumentation, making it ideal for point-of-care applications in resource-limited environments.
This study demonstrates the feasibility and effectiveness of hollow ZrO2@CdTe nanoparticles as advanced fluorescent labels in multiplex biosensing. Their structural stability, tunable emission, and compatibility with immunochromatographic formats position them as promising tools for future diagnostics. Future work will focus on improving cTnT detection sensitivity, reducing background fluorescence from test strips, and expanding the platform to include additional biomarkers for comprehensive cardiovascular risk assessment.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
