## 2 Applications of Biosensors in Bacteria Detection
### Recognition of Bacteria Using Biosensors
#### 2.1.3 Electrochemical Biosensors
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Biosensor Type** & **Detected Bacteria** & **Limit of Detection** & **Assay Time** & **Ref.** \\ \hline PEMC & _E. coli_ (O157:H7) & 10 cells/mL & \(\sim\)50 min & [PERSON] and [PERSON] [118] \\ \hline Microcantilever array biosensor & _E. coli_ (O157:H7, V, & & & \\  & _parahemolyticus,_ & & & \\ Microcantilever array biosensor & _Salmonella,_ & 1–9 CFU/mL & \(<\)1 h & [PERSON] et al. [114] \\  & _L. monocytogenes, Stigella_ & & & \\ \hline Microcantilever sensor & _Yersinia_ & no data & No data & [PERSON] et al. [115] \\ \hline Nanomechanical sensor & _E. coli_ & \(\sim\)10\({}^{3}\) CFU/mL & \(\sim\)45 min & [PERSON] et al. [149] \\ \hline Ultrahigh frequency mechanical resonators & _S. epidermidis_ & 1 CFU/mL & No data & [PERSON] et al. [116] \\ \hline Impedimetric sensor (conductive & & & \\ polycrystalline silicon & _E. coli_ & \(3\times 10^{2}\) CFU/mL & \(<\)1 h & [PERSON] et al. [126] \\  & interdigitated electrodes) & & & \\ \hline DNA-aptamer based impedance biosensor & _E. coli_ & 9 CFU/ mL & No data & [PERSON] et al. [123] \\ \hline Impedance biosensor & _S. typhimurium_ & 7 CFU/mL & 40 min & [PERSON] et al. [119] \\ \hline Impedance biosensor & _S. typhimurium_ & 19 CFU/mL & 1.5 h & [PERSON] et al. [120] \\ \hline Impedance biosensor & _S. typhimurium_ & 21 CFU/mL & 50 min & [PERSON] et al. [121] \\ \hline Impedance biosensor & _E. coli, S. aureus_ & 2 CFU/ mL & 30 min & [PERSON] et al. [125] \\ \hline Machine learning-based electrochemical impedance spectroscopy (EIS) & _E. coli_ & \(2\times 10^{6}\) and \(2\times 10^{7}\) CFU/mL & No data & [PERSON] et al. [150] \\ \hline Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) & _S. enteritidis_ & \(10^{3}\) CFU/mL & No data & [PERSON] et al. [128] \\ \hline Electrochemical impedance spectroscopy (EIS) & _S. epidermidis_ & \(10^{3}\)–\(10^{7}\) CFU/mL & No data & [PERSON] et al. [124] \\ \hline Impedimetric paper-based biosensor & Bacterial cultures from & \(1.9\times 10^{3}\) CFU/mL & 45 min & [PERSON] et al. [151] \\ biosensor & sewage sludge & \(1.9\times 10^{3}\) CFU/mL & 45 min & [PERSON] et al. [151] \\ \hline Impedance biosensor with & _S. typhimurium_ & \(10^{2}\) CFU/mL & 2 h & [PERSON] et al. [152] \\ immunomagnetic separation * & _S. typhimurium_ & \(10^{2}\) CFU/mL & 1 h & [PERSON] et al. [153] \\ \hline MEMS-based impedance biosensor & _E. coli_ & 1 CFU/mL & No data & [PERSON] et al. [131] \\ biosensor & _E. coli_ & \(1\) & \(\mathrm{CFU/mL}\) & No data & [PERSON] et al. [131] \\ voltammetry & _L. monocytogenes_ and & \(9\) CFU/mL for _L._ & \\  & _S. aureus_ & \(\sim\)3 CFU/mL & 1 min & [PERSON] and [PERSON] [132] \\ \hline Voltammetric biosensor & _S. aureus_ & 3–5 CFU/mL & 0.5 h & [PERSON] et al. [129] \\ \hline Potentiometric immunoassay & _S. typhimurium_ & 5 CFU/mL & \(<\)1 h & [PERSON] et al. [154] \\ \hline Amperometric biosensor & _E. coli_ & \(\mathrm{O157}\)-\(\mathrm{H7}\) & 1 CFU/mL & 1 h & [PERSON] et al. [135] \\ \hline Electrochemical biosensor & _P. aeruginosa_ & \(1.8\times 10^{-6}\) mol dm\({}^{-3}\) & 5 s & [PERSON] et al. [155] \\ \hline  & _E. coli,_ & & & \\ Electrochemical biosensor & _S. enteritidis,_ & \(1.\) & \(\mathrm{I}\) & \\  & _L. innocua,_ & \(50\) CFU/mL & 100 min & [PERSON] et al. [156] \\  & _P. aeruginosa_ and & & & \\  & _S. pneumoniae_ & & & \\ \hline Electrochemical biosensor & _Gram-negative bacteria with_ & & & \\  & _Toll-like receptor 4_ & & & \\ \hline Electrochemical aptasensor & _S. typhimurium_ & \(80\) CFU/mL & 2 h & [PERSON] et al. [122] \\ \hline Electrochemical TLR2/6 & _B. licheniformis,_ & \(10^{2}\) CFU/mL (_B. licheniformis_),_ & No data & [PERSON] et al. [158] \\ biosensors & _E. hirnea_ & \(10^{4}\) CFU/mL (_E. hirae_) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: \(Cont.\)
To conclude and summarize this section, label-free optical biosensors have certain advantages, i.e., relatively simple measurement procedures, application of parallel sen