Merck

Enhancement of enzymatic colorimetric response by silver island films on high throughput screening microplates.

Journal of immunological methods (2014-06-21)
Biebele Abel, Travis C Clement, Kadir Aslan
RESUMEN

In this study, we report the use of an enzyme-based hybrid platform, which is comprised of silver island films, enzymes (HRP and AP) and high-throughput screening (HTS) microplates, to enhance the colorimetric response of enzymatic reactions. The hybrid platform was designed in a two-step process: (i) deposition of SIFs onto HTS microplates with low, medium, and high loading (refers to the extent of the surface plasmon resonance peak of SIFs at 460 nm) using Tollen's reaction scheme; and (ii) attachment of b-BSA or BEA as linkers for the immobilization of enzymes. The presence of SIFs within the wells of the HTS microplates was confirmed using an optical spectrophotometer and real-color photography. Control experiments, where SIFs were omitted from the surfaces were carried out to confirm the effect of SIFs on the enzymatic colorimetric response. Significant colorimetric signal enhancement was observed for HRP or AP on SIFs (high loading) deposited HTS microplates using b-BSA (up to ~3-fold for AP and ~6-fold HRP) or BEA (up to ~7-fold for both HRP and AP), as compared to our control samples. The observed increase in colorimetric response can be attributed to the nature of BEA, which exposes surface-bound enzymes to the substrate present in bulk more efficiently than b-BSA. This study proves that SIFs can serve as a valuable tool to improve the signal output of existing bioassays carried out in HTS microplates, which can be applicable to the field biosensors and plasmonics.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Sodium hydroxide solution, 1.0 N, BioReagent, suitable for cell culture
Supelco
Hydrogen peroxide solution, ≥30%, for trace analysis
Sigma-Aldrich
Hydrogen peroxide solution, 34.5-36.5%
Millipore
Hydrogen peroxide solution, 3%, suitable for microbiology
Sigma-Aldrich
Hydrogen peroxide solution, 30 % (w/w) in H2O, contains stabilizer
Sigma-Aldrich
Boric acid-11B, ≥99 atom % 11B
Sigma-Aldrich
3-Ethyl-2,4-pentanedione, mixture of tautomers, 98%
Supelco
Phosphate Standard for IC, TraceCERT®, 1000 mg/L phosphate in water
Sigma-Aldrich
Hydrogen peroxide solution, contains potassium stannate as inhibitor, 30-32 wt. % in water, semiconductor grade, 99.999% trace metals basis
Sigma-Aldrich
Sodium phosphate dibasic solution, BioUltra, 0.5 M in H2O
Sigma-Aldrich
Hydrogen peroxide solution, tested according to Ph. Eur.
Sigma-Aldrich
Sodium hydroxide, BioUltra, for luminescence, ≥98.0% (T), pellets
Supelco
Sodium hydroxide solution, 49-51% in water, eluent for IC
Sigma-Aldrich
Sodium hydroxide solution, BioUltra, for molecular biology, 10 M in H2O
Supelco
Sodium hydroxide concentrate, 0.1 M NaOH in water (0.1N), Eluent concentrate for IC
Supelco
Hydrogen peroxide solution, 30 % (w/w), for ultratrace analysis
Sigma-Aldrich
Nitric-14N acid solution, ~10 N in H2O, 99.99 atom % 14N
Sigma-Aldrich
Sodium hydroxide, pellets, semiconductor grade, 99.99% trace metals basis
Sigma-Aldrich
Sodium hydroxide, ACS reagent, ≥97.0%, pellets
Sigma-Aldrich
Hydrogen peroxide solution, contains ~200 ppm acetanilide as stabilizer, 3 wt. % in H2O
Sigma-Aldrich
Sodium hydroxide, reagent grade, 97%, flakes
Sigma-Aldrich
Sodium hydroxide, beads, 20-40 mesh, reagent grade, 97%
Sigma-Aldrich
Hydrogen peroxide solution, 50 wt. % in H2O, stabilized
Sigma-Aldrich
Hydrogen peroxide solution, contains inhibitor, 35 wt. % in H2O
Sigma-Aldrich
Sodium hydroxide solution, 50% in H2O
Sigma-Aldrich
Sodium hydroxide, ultra dry, powder or crystals, 99.99% trace metals basis
Sigma-Aldrich
Sodium hydroxide, reagent grade, 97%, powder
Sigma-Aldrich
Sodium hydroxide, reagent grade, ≥98%, pellets (anhydrous)
Sigma-Aldrich
Sodium hydroxide, puriss. p.a., ACS reagent, K ≤0.02%, ≥98.0% (T), pellets
Sigma-Aldrich
Sodium hydroxide solution, 5.0 M