Patterned Plasmonic Nanoparticle Arrays for Microfluidic and Multiplexed Biological Assays

Abstract

For applications ranging from medical diagnostics and drug screening to chemical and biological warfare detection, inexpensive, rapid-readout, portable devices are required. Localized surface plasmon resonance (LSPR) technologies show substantial promise toward meeting these goals, but the generation of portable, multiplexed and/or microfluidic devices incorporating sensitive nanoparticle arrays is only in its infancy. Herein, we have combined photolithography with Hole Mask Colloidal lithography to pattern uniform nanoparticle arrays for both microfluidic and multiplexed devices. The first proof-of-concept study is carried out with 5- and 7-channel microfluidic devices to acquire one-shot binding curves and protein binding kinetic data. The second proof-of-concept study involved the fabrication of a 96-spot plate that can be inserted into a standard plate reader for the multiplexed detection of protein binding. This versatile fabrication technique should prove useful in next generation chips for bioassays and genetic screening.

Sub-monolayer silver loss from large gold nanospheres detected by surface plasmon resonance in the sigmoidal region

“…[45][46][47][48][49][50][51][52][53][54] Sigmoidal responses were observed as a function of the coverage of proteins (in log scale) on gold particles deposited on flat substrates. 55 This is similar to the Langmuir-Freundlich isotherm curve, 47 which is not an intrinsic response of silver layer on gold substrate. Sigmoidal response of silver coating on gold substrate has not been reported.…”

A comparison of nanoparticle-antibody conjugation strategies in sandwich immunoassays

“…These procedural points can have critical ramifications on the ability of a POC assay to be clinically useful. Gold NPs have been used extensively as contrast agents in a variety of micro/paperfluidic tests, and recent reports have shown these tests can be expanded beyond simple formats to fluidic arrays of various designs for multiplexing and lowering the limit of detection 14, 15 . Here, we compared approaches for conjugating antibodies to gold NPs and characterized the resulting NP-antibody conjugates in detecting a target biomarker in dipstick flow tests.…”

Microfluidics‐Implemented Biochemical Assays: From the Perspective of Readout

“…SPR mainly includes localized SPR (LSPR) and propagating SPR (PSPR), where the former one is based on the excitation of a single plasmonic nanoparticle by an external light field . He et al has applied multiplexed gold and silver nanohole arrays to achieve an amplified and multiplexed detection, where the LOD of the assay ranged from picomolar to nanomolar based on specific proteins . They have developed a new procedure to pattern the nanoparticle arrays with specific shapes onto the microfluidic channel via the combination of hole mask colloidal lithography with photolithography.…”

“…[61] He et al has applied multiplexed gold and silver nanohole arrays to achieve an amplified and multiplexed detection, where the LOD of the assay ranged from picomolar to nanomolar based on specific proteins. [62] They have developed a new procedure to pattern the nanoparticle arrays with specific shapes onto the microfluidic channel via the combination of hole mask colloidal lithography with photolithography. By using such a microfluidic device with patterned arrays and channels, they obtained the binding curves and protein binding kinetic data from the LSPR shifts and the intensity value.…”