# Sensor Micro and Nanoparticles for Microfluidic Application
## 4 Microfluidic Systems for Chemosensing
### Particle-Based Gas Sensing
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Application** & **Detection Method** & \begin{tabular}{c} **Particle** \\ **Type** \\ \end{tabular} & **Size** & \begin{tabular}{c} **Fluidic** \\ **System** \\ \end{tabular} & **Main Advantage** & **Ref.** \\ \hline Cocaine, & & & & four-channel & \begin{tabular}{c} Simultaneous, sensitive \\ and specific detection \\ with limit of detection \\ of 4 \(\upmu\)g for cocaine, \\ codeine and \\ methamphetamine \\ drugs. \\ \end{tabular} & \multirow{4}{*}{[69]} \\ Cocaine, & & & & four-channel & \begin{tabular}{c} Simultaneous, sensitive \\ and specific detection \\ with limit of detection \\ of 4 \(\upmu\)g for cocaine, \\ codeine and \\ methamphetamine \\ drugs. \\ \end{tabular} & \multirow{4}{*}{[70]} \\ Cocaine, & & & & four-channel & \begin{tabular}{c} Simultaneous, sensitive \\ and specific detection \\ with limit of detection \\ of 4 \(\upmu\)g for cocaine, \\ codeine and \\ methamphetamine \\ drugs. \\ \end{tabular} & \multirow{4}{*}{[69]} \\ Cocaine, & & & & & of \begin{tabular}{c} Simple, straightforward \\ and highly specific \\ protein analysis by the \\ naked eye and a flatbed \\ scanner, low sample \\ cost, good linear \\ relationship with the \\ detection limit of 20 pM \\ \end{tabular} & \multirow{4}{*}{[71]} \\ Chrombin & & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \hline \hline \end{tabular} \begin{tabular}{c} \multirow{3}{*}{Tuberculosis} & \multirow{3}{*}{Colorimetric assay} & \multirow{3}{*}{AuNPs} & \multirow{3}{*}{13 nm} & \begin{tabular}{c} Accurate, simple, \\ low-cost and rapid \\ analysis within 1 h, only \\ 200 \(\upmu\)L sample \\ consumption, limit of \\ ng/ml. \\ \end{tabular} & \multirow{3}{*}{[72]} \\ Cysteine & & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \hline \hline \end{tabular} \begin{tabular}{c} \multirow{3}{*}{Tuberculosis} & \multirow{3}{*}{Colorimetric assay} & \multirow{3}{*}{AuNPs} & \multirow{3}{*}{13 nm} & \begin{tabular}{c} 2-LED- \\ \(\upmu\)Spectro \\ photometer \\ \end{tabular} & \multirow{3}{*}{\begin{tabular}{c} low-cost, easy to use \\ and specific assay, \\ detection limit of 0.5 \\ pg/uL DNA \\ \end{tabular} & \multirow{3}{*}{[74]} \\ Glucose & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & \\ \cline{4-6}  & & & & \\ \hline \hline \end{tabular} \begin{tabular}{c} \multirow{3}{*}{Tuberculosis} & \multirow{3}{*}{Cyclic voltammetry} & \multirow{3}{*}{CS-RGO-NiNPs} & \multirow{3}{*}{32 nm} & \
\begin{tabular}{c} PDMS \\ microfluidic \\ device \\ \end{tabular} & \multirow{3}{*}{
\begin{tabular}{c} Linear detection range \\ up to 9 mM with limit \\ of detection of 4.1 \(\upmu\)M \\ glucose \\ \end{tabular} & \multirow{3}{*}{[75]} \\ Hemoglobin & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \cline{4-6}  & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._performed using diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS). For testing produced sensors, four gas samples, which contained CO, CH\({}_{4}\), ethanol or toluene were measured at humid and dry conditions. By comparing the measurement results obtained using SnO\({}_{2}\) surfaces loaded with gold nanoparticles or AuPd composite to results obtained using Pd-loaded SnO\({}_{2}\) surface, it was shown that the detection properties strongly depended on SnO\({}_{2}\) surface doping with different nanoparticles. As a result, gold nanoparticle deposition on the SnO\({}_{2}\) increased the sensor signals for all samples and reduced the water vapor interference.