Nanowire Nanosensors for Highly Sensitive and Selective Detection of Biological and Chemical Species

Abstract

Boron-doped silicon nanowires (SiNWs) were used to create highly sensitive, real-time electrically based sensors for biological and chemical species. Amine- and oxide-functionalized SiNWs exhibit pH-dependent conductance that was linear over a large dynamic range and could be understood in terms of the change in surface charge during protonation and deprotonation. Biotin-modified SiNWs were used to detect streptavidin down to at least a picomolar concentration range. In addition, antigen-functionalized SiNWs show reversible antibody binding and concentration-dependent detection in real time. Lastly, detection of the reversible binding of the metabolic indicator Ca2+ was demonstrated. The small size and capability of these semiconductor nanowires for sensitive, label-free, real-time detection of a wide range of chemical and biological species could be exploited in array-based screening and in vivo diagnostics.

Peptide nucleic acids on microarrays and other biosensors

“…Additionally, real-time measurement during the hybridization process would be possible. One step in this direction was the development of amine-and oxidefunctionalized silicon nanowires [39] (Figure 4c). Depositing PNA probes, Hahm and Lieber [40] were able to discriminate between wild-type and mutation sequences of the cystic fibrosis transmembrane receptor gene.…”

Screening-Limited Response of NanoBiosensors

“…2a, [1][2][3][4][5]), (ii) linear dependence on pH which is crucial for protein detection (Fig. 2b, [5,6]), (iii) non-linear dependence of sensitivity on electrolyte concentration (Fig. 2c, [7]), and (iv) anomalous time-dependence of sensor response instead of the classical Langmuir-type response (Fig.…”

Simultaneous Tunable Selection and Self-Assembly of Si Nanowires from Heterogeneous Feedstock

“…for chemical/biological sensing applications and their ability to be solution-processed and assembled from "semiconducting inks" using various alignment techniques, make them potential key building blocks for the manufacturing of chemical and biological sensors, [1][2][3] high performance field-effect transistors (FETs), [4][5][6] optical devices, 7,8 memory elements [9][10][11] and energy harvesting. 12,13 The availability of high quality semiconducting NWs in scalable quantities remains one of the main challenges for NW-based printed electronics.…”