Highly effective protein detection for avidin-biotin system based on colloidal photonic crystals enhanced fluoroimmunoassay.
There has been immense interest in both instruments and methods to enhance fluorescence signal and achieve highly sensitive fluoroimmunoassay (FIA). In this paper, we present a facile, low-cost and general method of biotinylated colloidal photonic crystal (PC) to improve the FIA of avidin (avidin FIA). The fluorescence signal intensity of the avidin FIA on the colloidal PC can be enhanced over two orders of magnitude relative to the control sample, attributed to the large surface area, resonance field and coherent scattering effect of the colloidal PC. The detection limit is shrunk to 1/69 of that of the control sample. Furthermore, the signal to interference ratio (S/I ratio) is increased because the band-edge induced fluorescence enhancement is wavelength-selective. The interference fluorescence does not go up proportionally while the signal is significantly enhanced by the colloidal PCs. It is believed that the colloidal PC modified with biotin can act as an effective material for a general and sensitive fluoroimmunoassay.
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Weizhi
W
Shen
Mingzhu
M
Li
Liang
L
Xu
Shutao
S
Wang
Lei
L
Jiang
Yanlin
Y
Song
Daoben
D
Zhu
D001360:Avidin / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation*; D001710:Biotin / Q000737:chemistry* / Q000276:immunology; D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015200:Fluoroimmunoassay / Q000295:instrumentation*; D017785:Photons; D040081:Protein Array Analysis / Q000295:instrumentation*
D003102:Colloids; D001360:Avidin; D001710:Biotin