# Silver Nanowires: Synthesis, Antibacterialativity and Biomedical Applications
## 2 Synthesis of AgNWs  
AgNW synthesis has developed greatly over the last thirty years. Several solution methods have been studied and are extensively reviewed by [PERSON] and [PERSON] [20]; subsequent progress in the field has led to the development of two major methods by which AgNWs can be synthesized, referred to as hard- and soft-template methods. Some key findings are reported in Table 1. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & & **Hard-Template Synthesis** & **Reference** \\ \hline
**AgNW Diameter** & **AgNW Length** & **Microbes Examined** & **Key Findings** & **Reference** \\ \hline
7 nm & 50 nm—1 \(\mu\)m & Not tested & Microporous silica (BA-15) template & [21] \\  & & & Length controlled via loading percentage, annealing temp/time & \\ \hline
7-8 nm & over 1 \(\mu\)m & Not tested & Microporous silica (BA-15) template & [22] \\  & & & Length controlled by reduction time & \\ \hline
7 nm & up to 4 \(\mu\)m & Not tested & Surface modification of SBA-15 & [23] \\  & & & SBA-15 synthesis at low temp, AgNPs nuts must be capped & \\ \hline \multicolumn{4}{c}{**Soft-Template Synthesis**} \\ \hline
**AgNW Diameter** & **AgNW Length** & **Microbes Examined** & **Key Findings** & **Reference** \\ \hline
30–40 nm & 2-50 \(\mu\)m & Not tested & Temperature and seed number important & [24] \\ \hline
30–40 nm & Not stated & Not tested & Pt nanoparticle seeding & [25] \\  & & & AgNOs and PVP added dropwise & [26] \\ \hline
45–60 nm & 2-5 \(\mu\)m & Not tested & Self-seeding with syringe pump; PVP to AgNOs molar ratio critical; PVP molecular weight important & [26] \\ \hline
100 nm & 10-50 \(\mu\)m & Not tested & Addition of CuCl\({}_{7}\) or CuCl important & [27] \\ \hline
170-310 nm & Not stated & Not tested & Solovthermal method with H\({}_{2}\)S & [28] \\  & & & Controllable diameters by H\({}_{2}\)S concentration & [28] \\ \hline
50 nm & 20 \(\mu\)m & Not tested & NaCl instead of CuCl\({}_{2}\) & [29] \\ \hline
30–70 nm & 1-25 \(\mu\)m & Not tested & Altering temp and time controls size of generated AgNPs nuts & [30] \\ \hline
30-50 nm & Not stated & Not tested & 100\({}^{\circ}\) C w/o PVP & [31] \\
80 nm & & & 200\({}^{\circ}\) C w/o PVP & [31] \\ \hline
60-90 nm & 6-12 \(\mu\)m & Not tested & Glycerol substituted for ethylene glycol (green process) & [23] \\ \hline \multicolumn{4}{c}{**Antibacterial Activity of AgNW's Synthesised by Soft-Template Methods**} \\ \hline
**AgNW Diameter** & **AgNW Length** & **Microbes Examined** & **Key Findings** & **Reference** \\ \hline
70-150 nm & 3-8 \(\mu\)m & \
\begin{tabular}{c} _E. coli_ MK1061 \\ (pSLlux) \\ \end{tabular} &
\begin{tabular}{c} Boltzmannent recombinant _E. coli_ employed \\ No shape-dependent AgNP toxicity \\ \end{tabular} & [33] \\ \hline
60 nm & 2-4 \(\mu\)m & _E. coli_ ATCC 29922 & Shape of AgNP’s dictates contact & [34] \\  & & & Episosed facet type important & [35] \\ \hline
50-100 nm & 1-20 \(\mu\)m & _S. aureus_ DSMZ 1104 & Particle morphology dictates dissolution and inhibition & [35] \\ \hline
50 nm & 10-100 \(\mu\)m & \
\begin{tabular}{c} _E. coli_ K-12 \\ _S. aureus_ \\ \end{tabular} &
\begin{tabular}{c} AgNW’s added to graphene oxide (GO) sheets \\ Enhanced activity when CO and AgNW combined \\ \end{tabular} & [6] \\  & & & Sower release of Ag/enhanced ROS & \\ \hline \end{tabular}
\end{table} 
Table 1: Synopsis of synthesis methods, antibacterial activity and emerging applications found in this review.