TY - JOUR
T1 - High-throughput fabrication of high aspect ratio Ag/Al nanopillars for optical detection of biomarkers
AU - Garifullina, Ainash
AU - Shen, Amy Q.
N1 - Funding Information:
The authors acknowledge the financial support from the Okinawa Institute of Science and Technology Graduate University (OIST) with subsidy funding from the Cabinet Office, Government of Japan. A. G. is a JSPS DC2 fellow (Japan Society for Promotion of Science) and this work is supported by JSPS KAKENHI (Grant No. 21J10403). The authors also thank Mr Kazumi Toda-Peters from the Micro/Bio/Nanofluidics Unit at OIST for useful discussions, assistance with experimental design of the project, and help with visuals and schematics of the manuscript.
Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2021/11/14
Y1 - 2021/11/14
N2 - Nanomaterial-based optical techniques for biomarker detection have garnered tremendous attention from the nanofabrication community due to their high precision and enhanced limit of detection (LoD) features. These nanomaterials are highly responsive to local refractive index (RI) fluctuations, and their RI unit sensitivity can be tuned by varying the chemical composition, geometry, and dimensions of the utilized nanostructures. To improve the sensitivity and LoD values of these nanomaterials, it is common to increase both dimensions and aspect ratios of the fabricated nanostructures. However, limited by the complexity, prolonged duration, and elevated costs of the available nanofabrication techniques, mass production of these nanostructures remains challenging. To address not only high accuracy, but also speed and production effectiveness in these nanostructures' fabrication, our work reports, for the first time, a fast, high-throughput, and cost-effective nanofabrication protocol for routine manufacturing of polymer-based nanostructures with high sensitivity and calculated LoD in the pM range by utilizing anodized aluminum oxide (AAO) membranes as templates. Specifically, our developed platform consists of arrays of nearly uniform polystyrene nanopillars with an average diameter of ∼185 nm and aspect ratio of ∼11. We demonstrate that these nanostructures can be produced at a high speed and a notably low price, and that they can be efficiently applied for biosensing purposes after being coated with aluminum-doped silver (Ag/Al) thin films. Our platform successfully detected very low concentrations of human C-reactive protein (hCRP) and SARS-CoV-2 spike protein biomarkers in human plasma samples with LoDs of 11 and 5 pM, respectively. These results open new opportunities for day-to-day fabrication of high aspect ratio arrays of nanopillars that can be used as a base for nanoplasmonic sensors with competitive LoD values. This, in turn, contributes to the development of point-of-care devices and further improvement of the existing nanofabrication techniques, thereby enriching the fields of pharmacology, clinical analysis, and diagnostics.
AB - Nanomaterial-based optical techniques for biomarker detection have garnered tremendous attention from the nanofabrication community due to their high precision and enhanced limit of detection (LoD) features. These nanomaterials are highly responsive to local refractive index (RI) fluctuations, and their RI unit sensitivity can be tuned by varying the chemical composition, geometry, and dimensions of the utilized nanostructures. To improve the sensitivity and LoD values of these nanomaterials, it is common to increase both dimensions and aspect ratios of the fabricated nanostructures. However, limited by the complexity, prolonged duration, and elevated costs of the available nanofabrication techniques, mass production of these nanostructures remains challenging. To address not only high accuracy, but also speed and production effectiveness in these nanostructures' fabrication, our work reports, for the first time, a fast, high-throughput, and cost-effective nanofabrication protocol for routine manufacturing of polymer-based nanostructures with high sensitivity and calculated LoD in the pM range by utilizing anodized aluminum oxide (AAO) membranes as templates. Specifically, our developed platform consists of arrays of nearly uniform polystyrene nanopillars with an average diameter of ∼185 nm and aspect ratio of ∼11. We demonstrate that these nanostructures can be produced at a high speed and a notably low price, and that they can be efficiently applied for biosensing purposes after being coated with aluminum-doped silver (Ag/Al) thin films. Our platform successfully detected very low concentrations of human C-reactive protein (hCRP) and SARS-CoV-2 spike protein biomarkers in human plasma samples with LoDs of 11 and 5 pM, respectively. These results open new opportunities for day-to-day fabrication of high aspect ratio arrays of nanopillars that can be used as a base for nanoplasmonic sensors with competitive LoD values. This, in turn, contributes to the development of point-of-care devices and further improvement of the existing nanofabrication techniques, thereby enriching the fields of pharmacology, clinical analysis, and diagnostics.
KW - Aluminum Oxide/chemistry
KW - Biomarkers/blood
KW - Biosensing Techniques
KW - C-Reactive Protein/analysis
KW - COVID-19/diagnosis
KW - Dimethylpolysiloxanes/chemistry
KW - High-Throughput Screening Assays/methods
KW - Humans
KW - Limit of Detection
KW - Nanostructures/chemistry
KW - Point-of-Care Systems
KW - Polystyrenes/chemistry
KW - SARS-CoV-2/isolation & purification
KW - Silver/chemistry
KW - Spike Glycoprotein, Coronavirus/blood
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U2 - 10.1039/d1tb01556g
DO - 10.1039/d1tb01556g
M3 - Article
C2 - 34647953
AN - SCOPUS:85118775912
SN - 2050-7518
VL - 9
SP - 8851
EP - 8861
JO - Journal of Materials Chemistry B
JF - Journal of Materials Chemistry B
IS - 42
ER -