Antibody‐Conjugated Rubpy Dye‐Doped Silica Nanoparticles as Signal Amplification for Microscopic Detection of Vibrio cholerae O1

Abstract

This study demonstrated the potential application of antibody-conjugated Rubpy dye-doped silica nanoparticles for immunofluorescence microscopic detection ofVibrio choleraeO1. The particle synthesis of 20X of the original ratio was accomplished yielding spherical nanoparticles with an average size of45±3 nm. The nanoparticles were carboxyl functionalized and then conjugated with either monoclonal antibody or polyclonal antibody againstV. choleraeO1. The antibody-conjugated nanoparticles were tested with two target bacteria and three challenge strains. The result showed that monoclonal antibody-conjugated Rubpy dye-doped silica nanoparticles could be effectively used as signal amplification to detectV. choleraeO1 under a fluorescence microscope. Their extremely strong fluorescence signal also enables the detection of a single cell bacterium.

Validation of a Rapid Visual Screening of Campylobacter jejuni in Chicken Using Antibody-Conjugated Fluorescent Dye-Doped Silica Nanoparticle Reporters

“…The size of FDS-NPs of approximately 30-60 nm was consistent with that previously reported [14,15,17,18]. Thepwiwatjit et al [14] reported the FDS-NPs with relatively narrow size of 29-43 nm. The size distribution usually depended on synthesis techniques, equipment, time, maximum speed, size of magnetic stirrer, and container.…”

“…Our research group had developed silica and ferromagnetic nanoparticle-based detection for Vibrio cholerae in seafoods, Salmonella spp., E. coli O157:H7, and C. jejuni in poultry and products [14][15][16][17][18]. These methods showed potential applications in the routine use.…”

“…Modifications. Synthesis of FDS-NPs and surface modifications were carried out as previously described [14,15,17,18]. Briefly, mixtures of cyclohexane (75 ml), Triton X-100 (17.7 ml), and n-hexanol (18 ml) as oil, surfactant, and cosurfactant phases, respectively, were mixed with 4.8 ml aliquots of Rubpy dye solution (20 mM in deionized water).…”

Rubpy Dye‐Doped Silica Nanoparticles as Signal Reporter in a Dot Fluorescence Immunoassay Strip

“…Rubpy dye-doped silica nanoparticles (RSNPs) were synthesized using a water-in-oil microemulsion technique as described in [20]. Briefly, cyclohexane, aqueous Rubpy dye solution, Triton X-100, and n-hexanol were used as oil phase, water phase, surfactant, and cosurfactant, respectively.…”

“…However, using these nanomaterials as detection particles requires specific equipment to detect or monitor their fluorescence signals such as spectrofluorometer [9,13], fluorescence microscope [9,17,20], confocal microscope [12,21] and flow cytometer [22]. This necessity might be the reason that there is no study reporting an employment of these materials in a strip assay for a point-of-care or field test although they have been of interest as a fascinating fluorescent probe and attracted widespread application in biology and medicine for years.…”