## 2 Thermo-Responsive Molecularly Imprinted Polymers  
The biochemical processes of natural receptors, such as enzyme-catalysis, exhibit extremely sensitive dependence on temperature [24, 90]. To simulate the temperature-dependent recognition and catalytic capacity, several thermo-responsive MIPs have been developed in parallel with a plethora of non-imprinted thermo-responsive polymers [24, 38, 40]. These polymers can exhibit either a lower critical solution temperature (LCST), below which they are a hydrophilic state, or an upper critical solution temperature, above which they are hydrophilic. The most widely studied synthetic thermo-responsive polymer is poly (\(N\)-isopropylacrylamide) (PNIPAm), which undergoes a reversible phase transition at 32 \({}^{\circ}\)C (also called as Lower Critical Solution Temperature, LCST) in water, changing from hydrophilicity below the temperature to hydrophobicity above it [43, 91]. The phase transition from soluble stretching polymer chain to insoluble coil-globule state is attributed to the decreasing enthalpic contribution of \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Stimulus** & **Template** & **Monomer and cross-linker** & **Form of MIPs** & **Reference** \\ \hline \multirow{6}{*}{pH-responsive} & Propranolol & NIPAm, DMAEMA, EGDMA & Particle with brush & [58] \\ \cline{2-5}  & DXP & HEMA, DMAEMA, EGDMA & Particle & [59] \\ \cline{2-5}  & (S)-omeprazole & HEMA, PCL-T, EGDMA & Particle & [60] \\ \cline{2-5}  & & AAc, acryloylancy, MBAA & Powders & [61] \\ \cline{2-5}  & Bisphenol-A & PES, MBAA & Particle & [62] \\ \cline{2-5}  & & MAA, EGDMA & Layer & [63] \\ \cline{2-5}  & HVA & NIPAM, 4-VP, hemin, AAM, EGDMA & Particle & [64] \\ \cline{2-5}  & Diclofenac & MAA, MAAm, 4-VP, EGDMA & Bulk & [65] \\ \cline{2-5}  & Insulin & MAA, PEG, MBA & Bulk & [66] \\ \hline \multirow{6}{*}{pH-responsive} & Caffe & MPABA, TRIM & Bulk & [67] \\ \cline{2-5}  & Bis(TBA)-\(N\)-\(Z\)-\(L\)-Glutamate & Di(ureideothyleneck)\(\underline{\text{tate}}\))\(\underline{\text{a}}\)obenzene, EGDMA & Bulk & [68] \\ \cline{2-5}  & Caffe or theophylline & MPABA, 4-(dimethylamino)pyridine, triethylamine, & & [69] \\ \cline{2-5}  & Parcatamol & MAPASA, MBAA & Bulk & [70] \\ \cline{2-5}  & 1,3,5-Benzenetriol & MAPASA, TTT & Bulk & [71] \\ \cline{2-5}  & Porphin & Azobenzene, DVB, Styrene & Bulk & [26] \\ \cline{2-5}  & Propranolol & NIPAAm, MPABA, EGDMA & Particle with brush & [38] \\ \cline{2-5}  & & DCPA-AZO-TESP, TEOS & Core-shell & [72] \\ \cline{2-5}  & 2,4-D & MazoPy, EGDMA & Particle & [73, 74] \\ \cline{2-5}  & & 4-((4-(4-(3-trimethoxysially) propoxy) phenyl) diazenyl) & & & [75] \\ \cline{2-5}  &phenyl 2-(4,4-dichlorophenoxyacy)acetate, TEOS & Bulk & [75] \\ \cline{2-5}  & 4-HA & PES/PES-N\({}_{1}\)-NH\({}_{2}\) & Microfiber & [76] \\ \cline{2-5}  & Ibuprofen & Azobenzene, EGDMA & Core-shell & [77] \\ \cline{2-5}  & BPPO-AZO-TPPSP, TEOS & Bulk & [78] \\ \cline{2-5}  & Guanine & MAPDIA, TEAMA & Bulk & [79] \\ \cline{2-5}  & PAF & MANFAB & Bulk & [80] \\ \cline{2-5}  & BPA & MAPASA, EGDMA & Core-shell & [81] \\ \cline{2-5}  & DA & PhAAAn, TEGDA, EGDMA & Membrane & [82, 83] \\ \hline \multirow{6}{*}{Biom molecule-responsive} & Cyt C or Lys & NIPAm, MAA, AAm, MBAA & Bulk & [52] \\ \cline{2-5}  & Hydrocortisone & HEMA, EGDMA & Bulk & [84] \\ \cline{2-5}  & & NSA, AAm, MBAA & Particle & [49] \\ \cline{2-5}  & AFP & acryloyl-Iectin, AAm, MBAA & Hydrogel & [85] \\ \cline{2-5}  & Thrombin & AM, MBAA & Hydrogel & [86] \\ \cline{2-5}  & dl-Norepinephrine & & & \\ \cline{2-5}  & Hydrochloride or & NIPAm, AAc, MBAA & Hydrogel & [87] \\ \cline{2-5}  & dl-Adrenaline hydrochloride & & & \\ \hline \multirow{2}{*}{Ion-responsive} & BSA & DMAPMA, NiPAm, MBAA & Bulk & [88] \\ \cline{2-5}  & Proton & NIPAm, AAc, MBAA & Particle & [89] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._water hydrogen-bonded to the polymer chain in comparison to the enthalpic gain of the system with increasing temperature.