Dataset on the Influence of Crosslinker Length on Antibody Orientation and the Performance of DLS-Based SARS-CoV-2 Biosensors
Description
Figure DB1. Characterization of the synthesized AuNPs revealed unimodal size distributions and red shifts in the plasmon resonance corresponding to progressive particle growth, confirming the successful synthesis of monodisperse, high-quality gold nanoparticles Figure DB2. SEM images of the AuNP sample (D53) showing a Feret diameter of 56.2 ± 6.1 nm, spherical morphology, and a unimodal diameter distribution. Figure DB3. ATR-FTIR spectra of the functionalized AuNPs showing characteristic bands of alkyl (C–H) chains at 2926 and 2848 cm⁻¹, and functional groups associated with carboxylic acids, including carbonyl (C=O) at 1647–1645 cm⁻¹ and carboxylate (COO⁻) at 1559–1556 cm⁻¹. Figure DB4. Details in FTIR spectra of AuNPs@crosslinkers: (a) CH2 stretching modes and (b) CH2 asymmetric band position as a function of the crosslinker’s chain size, in number of carbon atoms. Figure DB5. Deconvolution of the amide I bands for AuNPs@crosslinker-pAb revealed changes in the secondary structure profiles. Figure DB6. Stability analysis of the biosensor based on variations in hydrodynamic diameter and polydispersity index over a 60-day period. Figure DB7. BCA assay results for quantification of unbound polyclonal antibodies after conjugation, showing that AuNPs@MUA-pAb consistently exhibited the lowest concentration of unbound antibodies.
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Dynamic light scattering (DLS) measurements were performed with Zetasizer Lab Blue (Malvern) instrument. All measurements were conducted at 25 °C using either 50 µL or 1 mL polystyrene cuvettes, with triplicate readings taken to determine the mean and standard deviation. The hydrodynamic diameters (DH) and polydispersity index (PDI) reported correspond to Z-average values, calculated as the average of three measurements. UV-Vis absorption spectra were acquired at room temperature using a Cary 60 UV-Vis spectrophotometer (Agilent) with 3.5 mL quartz cuvettes (10 mm path length). Scanning electron microscopy (SEM) images were obtained with a Magellan TM 400 field emission gun (FEG) at accelerating voltage of 15 kV and a beam current of 0.10 nA. The diameters of the AuNPs were measured using ImageJ software (version 1.53e), and size distribution histograms were generated for each sample. The average particle size and distribution width were determined by fitting the histograms with a Gaussian function using Gnuplot software (version 5.4). Fourier transform infrared (FTIR) spectroscopy was carried out using a Thermo Nicolet iS50 spectrophotometer, with spectra recorded from 4000 to 600 cm⁻¹ at a resolution of 4 cm⁻¹, averaging 256 scans per measurement. A background was collected in the same instrumental conditions before each measurement. For sample preparation, dispersions were concentrated by centrifugation at 4000 rpm for 12 min at 20 °C, with 1100 μL of the supernatant removed. A drop of each concentrated sample was applied onto the attenuated total reflectance (ATR) crystal, and measurements were conducted after a film had formed on the crystal surface (ca. 40min) of the FTIR apparatus. FTIR data analysis was performed using GraphPad Prism (version 8.0.2) and OriginPro (version 9).
Institutions
- Universidade Federal Fluminense Instituto de Quimica