Enhancing nanoparticle-based visible detection by controlling the extent of aggregation.
Visible indication based on the aggregation of colloidal nanoparticles (NPs) is highly advantageous for rapid on-site detection of biological entities, which even untrained persons can perform without specialized instrumentation. However, since the extent of aggregation should exceed a certain minimum threshold to produce visible change, further applications of this conventional method have been hampered by insufficient sensitivity or certain limiting characteristics of the target. Here we report a signal amplification strategy to enhance visible detection by introducing switchable linkers (SLs), which are designed to lose their function to bridge NPs in the presence of target and control the extent of aggregation. By precisely designing the system, considering the quantitative relationship between the functionalized NPs and SLs, highly sensitive and quantitative visible detection is possible. We confirmed the ultrahigh sensitivity of this method by detecting the presence of 20 fM of streptavidin and fewer than 100 CFU/mL of Escherichia coli.
Center for Agricultural Biomaterials, Seoul National University, Seoul, 151-742, Republic of Korea.
Seokwon
S
Lim
Ok Kyung
OK
Koo
Young Sang
YS
You
Yeong Eun
YE
Lee
Min-Sik
MS
Kim
Pahn-Shick
PS
Chang
Dong Hyun
DH
Kang
Jae-Hyuk
JH
Yu
Young Jin
YJ
Choi
Sundaram
S
Gunasekaran
D001422:Bacterial Adhesion; D058491:Bacterial Load / Q000379:methods; D002462:Cell Membrane / Q000737:chemistry; D003124:Colorimetry; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology / Q000302:isolation & purification; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013053:Spectrophotometry; D019809:Streptavidin / Q000737:chemistry*
D012710:Serum Albumin, Bovine; D006046:Gold; D019809:Streptavidin