# A Review: Using Multiple Templates for Molecular Imprinted Polymer: Is It Good?
## 3 A Review of MT-MIPs That Have Been Created
### Template  
#### 3.1.1 Drugs  
The most widely used templates in MT-MIP synthesis are drugs because some drugs leave residues that are toxic to the environment and the body. Hence, there is an urgency to analyse drug levels in the environment and humans [103; 104; 105; 106; 107]. The existence of drug residues in this environment is due to industrial waste, expired drug products, hospital waste, and the metabolic products of human and animal excretion [105]. Therefore, an efficient, low-cost, highly sensitive, and fast analytical method is required to detect these drugs [108; 109; 110]. MT-MIPs represent a solution to this problem. The drugs used as templates in MT-MIP are mostly drugs in the same class (see Table 3). This is to facilitate the selection of other components, such as monomers, crosslinkers, initiators, and porogens [28]. The more similar the basic structure of a compound, the more similar the physicochemical properties of the compound will be. The physicochemical properties of the template determine the other components that will be selected [69], for example, selecting monomers considering their functional groups and porogens based on the polarity of the template [111]. Examples of drugs that have been used for MT-MIP templates are NSAIDs, cephalospororin antibiotics, and sulphonamide antibiotics. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Template** & **Monomer** & \
\begin{tabular}{c} **Polymerisation** \\ **Method** \\ \end{tabular} & **Qmax (mg/g)** & **IF** &
\begin{tabular}{c} **Application of** \\ **MT-MIP** \\ \end{tabular} & **Reference** \\ \hline Acetaminophen & \multirow{2}{*}{APTES} & Bulk & 8.76 & 4.09 & SPE & [59] \\ Codeine & & polymerisation & 6.29 & 4.16 & & \\ \hline Cefoperazone & \multirow{2}{*}{MAA} & Bulk & 0.0027 & 4.1 & & \\ Cefazolin & & polymerisation & 0.0029 & 3.3 & SPE & [75] \\ Cephalexin & & & 0.0026 & 3.4 & & \\ \hline Ginsnoside Rb1 & \multirow{2}{*}{AM} & Surface & \multirow{2}{*}{-} & \multirow{2}{*}{2.11} & \multirow{2}{*}{SPE} & [112] \\ Ginsenoside Rg1 & & polymerisation & & & & \\ \hline Ibuprofen & \multirow{4}{*}{2-VP} & Precipitation & & 7.6 & & \\ Naproxen & & & 4.8 & & \\ Ketoprofen & & polymerisation & - & 3.5 & SPE & [113] \\ Dclofenac & & & & 5.2 & & \\ Clofibric acid & & & 4.1 & & \\ \hline Naproxen & \multirow{4}{*}{2-VP} & Bulk & \multirow{4}{*}{-} & \multirow{4}{*}{SPE} & [73] \\ Ibuprofen & & & & & & \\ Dclofenac & & & & & \\ \hline Naproxen & \multirow{4}{*}{2-VP} & Bulk & \multirow{4}{*}{-} & \multirow{4}{*}{SPE} & [33] \\ Ibuprofen & & & & & \\ Ibuprofen & & polymerisation & - & & \\ \hline Ibuprofen & \multirow{4}{*}{2-VP} & Bulk & \multirow{4}{*}{-} & \multirow{4}{*}{SPE} & [32] \\ Dclofenac & & & & & \\ \hline Ruin & \multirow{4}{*}{2-VP} & Bulk & 0.025 & & \\ Scoparone & & oxysilane- & polymerisation & 0.057 & - & SPE & [114] \\ Quercetin & & methacrylic & & 0.025 & & \\ \hline Sulphadiazine & \multirow{4}{*}{4-vinylbenzoic acid} & Precipitation & & & & \\ \cline{1-1} Sulphamethazine & \multirow{4}{*}{4-vinylbenzoic acid} & Precipitation & & & & \\ \cline{1-1} Sulphamethazine & \multirow{4}{*}{4-vinylbenzoic acid} & polymerisation & & & & SPE & [115] \\ Sulphadoxine & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Drugs used as templates in multi-template molecularly imprinted polymers. The monomers that have been used in MT-MIP are mostly monomers for non-covalent molecular imprinting procedures, namely MAA, AM, 2-VP, 4-VP, 4-vinylbenzoic acid, and APTES. Likewise, a crosslinker is used to form non-covalent interactions. The most widely used crosslinker is EGDMA. Non-covalent molecular imprinting has been chosen because of the simple method and easy template removal process [117]. The porogens used are mostly non-polar. However, semi-polar porogens have also been chosen based on the polarity of the template used [111]. Some of the porogens that have been used in MT-MIP synthesis are toluene for NSAIDs and sulpha antibiotics and acetonitrile for cephalospor antibiotics.