2. Materials and methods
2.1. Materials and chemicals
All reagents were purchased from Sigma-Aldrich Chemical Co.
and used as received without further purification. THF (Labscan)
was dried over Na/benzophenone and distilled before use. All
chemical reactions were carried out under a nitrogen atmosphere
by using Schlenk techniques. 1H and 13C NMR spectra were measured
on a Bruker AV 400 spectrometer in deuterated chloroform.
Goat anti-Rabbit Antibodies (Gt- RbIgG) were used as capture
antibodies, and Rabbit antibodies (RbIgG) as the analyte, which
were purchased from Arista Biologicals Inc. Whatman® Chromatographic
Paper 1Chr was purchased from Sigma-Aldrich Chemical
Co. and used as received. Unless otherwise specified, ultrapure
water obtained from a Millipore water purification system (MilliQ)
was used to prepare aqueous solutions. 0.01 m pH 7.4 phosphate
buffer solution (1x PBS) was used as buffer for antibody immobilization.
A 1% solution of BSA in 1x PBS was used as blocking
buffer to block residual sites on paper to minimize non-specific
adsorption. An aqueous 0.5% sodium dodecyl sulfate (SDS) solution
was used to wash away unbound reagents. An office puncher was
purchased from a local shop in Hong Kong for paper pad cut out.
Polystyrene plates were obtained from Axygen Scientific Pipette
Tip boxes for 5–200 L tips. For the top-down fabrication of the
TPEDH nanoparticles a Brandson Sonifier 450 was used. BioRad Gel
Doc XR for fluorescence image taking ofthe paper pads. Image analysis
and nanoparticle characterization, ImageJ software was used.
Zeta Plus BIC (Brookhaven Instruments Corporation) was used to