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50 to 280 nm (mean number distribution byĭLS) for detection of 100 pg Of test line for antibody modified PtNCs (150 pM) varying in sizeįrom ca. Were synthesized in the presence of different gold nanoparticle seedĬoncentrations: A, 5 nM B, 1.2 nM C, 0.6 nM D, 0.3 nM E, 0.15 (d) Number distribution of the hydrodynamic diameter of PtNCs formedīy varying : measured by dynamic light scattering. Spots consistent with polycrystalline platinum with an FCC lattice. (iv) Selected area electron diffraction (SAED) pattern takenįrom a single PtNC ( ca. Inset shows the lattice fringes corresponding to platinum (111) and TEM image of an individual PtNC formed from 0.3 nM seed concentration. Size: (i) 5 nM seeds and (ii) 0.3 nM seeds. Of PtNCs synthesized with varying AuNP seed concentrations to control PtNCs incubated in serological and protein-rich environments up toĢ4 h ( n = 6). Of PVP, significant aggregation occurred. Influence of PVP molecular weight on PtNC catalytic activity, measuredīy the absorbance at 652 nm corresponding to the oxidation of TMB (PVP) as a stabilizer and l-ascorbic acid as a reducing agent. Structure (PtNC), where 15 nm gold nanoparticles are used as seedsįor subsequent platinum overgrowth in the presence of polyvinylpyrrolidone (a) Scheme showing synthesis of Au–Pt core–shell HIV detection biorthogonal chemistry broad dynamic range enzyme mimic lateral flow immunoassay nanobodies point-of-care porous platinum core−shell nanoparticles. This diagnostic may be readily adapted for detection of other biomolecules as an ultrasensitive screening tool for infectious and noncommunicable diseases and can be capitalized upon in PoC settings for early disease detection. This provides a versatile absorbance-based and rapid LFIA with sensitivity capable of significantly reducing the HIV acute phase detection window. mL -1) and the detection of acute-phase HIV in clinical human plasma samples in under 20 min.
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Harnessing the catalytic amplification of PtNCs enabled naked-eye detection of p24 spiked into sera in the low femtomolar range (ca. We explored the application of antibody-functionalized PtNCs with strategically and orthogonally modified nanobodies with high affinity and specificity toward p24 and established the key larger nanoparticle size regimes needed for efficient amplification and performance in LFIA. We report the synthesis and characterization of porous platinum core-shell nanocatalysts (PtNCs), which show high catalytic activity when exposed to complex human blood serum samples. To address this, we developed a serum-stable, nanoparticle catalyst-labeled LFIA with a sensitivity surpassing that of both current commercial and published sensitivities for paper-based detection of p24, one of the earliest and most conserved biomarkers of HIV. Paper-based lateral flow immunoassays (LFIAs) are one of the most widely used point-of-care (PoC) devices however, their application in early disease diagnostics is often limited due to insufficient sensitivity for the requisite sample sizes and the short time frames of PoC testing.