Well-oriented nanowell array metrics for integrated digital nanobiosensors

Abstract

Nanofabrication technologies should be useful for developing highly sensitive, reproducible nanobiosensors. This letter presents a nanometric system that is composed of well-oriented nanowells. The geometry permits only one or a few biomolecules to enter and become attached to nanosized gold dots. This nanoarray is easily fabricated using current nanolithography technology. When the authors applied this array to highly sensitive electrochemical DNA detection, they obtained a two-orders-of-magnitude enhancement in sensitivity. This nanometric system could be applied to numerous other integrated digital biosensors.

Integrated nanostructures for direct detection of DNA at attomolar concentrations

“…1 Nucleic acids are biomarkers of central importance, bringing a great deal of attention to the development of nucleic acids biosensors. 2 In previous reports, the surface of a sensor is typically modified with nucleic acids probes capable of generating an optical, 3-8 gravimetric, 9 piezoelectric, 10 electrical or electrochemical [11][12][13][14][15][16] signal when hybridization with a complementary sequence occurs.…”

Molded Nanowell Electrodes for Site‐Selective Single Liposome Arrays

“…[38,39] The deposition of single- FLVs was confirmed by AFM measurements as seen from the three-dimensional images in panel i) and ii) of Figure 2b, demonstrating that the spherical geometry of liposome was maintained after deposition without deformation (i.e., formation of lipid mono-or bilayer by vesicle fusion). Once the liposomes were captured within NWs, the gold electrode could be completely shielded from the electrolyte solution, thus significantly reducing signal-to-noise ratio.…”

“…A final phospholipids concentration of liposome used in this research was 1 mM. Details on the synthesis and characterization of the FLVs can be found elsewhere [39].…”

“…This is clearly advantageous over bare gold electrode or microscale electrode where a fraction of the electrode surface is exposed to the electrolyte solution even after deposition of the liposomes. [38,39] In our experiments, NWs of two different heights (∼ 70 nm and ∼ 200 nm) were tested as to whether the docking is affected by the height of NWs. The height was controlled by using different concentration of the PEG solution (2 and 5 wt % for the lower and higher height, respectively) while maintaining the other conditions the same.…”

Simple Patterning via Adhesion between a Buffered‐Oxide Etchant‐Treated PDMS Stamp and a SiO2 Substrate

“…4f) could utilize a well-oriented microwell to immobilize biomolecules in biosensor applications. [34] Figure 8a is an optical microscopy image obtained from a SiO 2 substrate after the transfer of a BOE-treated PDMS pattern to the prepatterned Au electrodes of Figure 7c. The microscopy image shows that the PDMS layers were transferred only to the bare SiO 2 region and not to the patterned Au area, as observed in the double-printing process of Figure 5a.…”