## 3 Results and Discussion
Figure 1: (**a**) Dependence of the pseudo-first-order rate constant for the hydrolysis of **1b** on the solution pH at 25 \({}^{\circ}\)C. The nanoparticles were prepared using 1.0 equiv of DVB; (**b**) Dependence of the pseudo-first-order rate constant for the hydrolysis of **1b** on the solution pH at 25 \({}^{\circ}\)C. The nanoparticles were prepared using 0.5 equiv of DVB. [**1b**] = 25 \(\upmu\)M. [NINP] = 5 \(\upmu\)M.  
A parameter frequently used to evaluate the effectiveness of molecular imprinting is the imprinting factor, frequently determined by the ratio in the binding of the imprinted polymer for the template over that of the nonimprinted polymer. Although the insolubility of the template **T** in water makes direct determination of the binding constants challenging, we could use the \(K_{\text{M}}\) values of the imprinted and nonimprinted nanoparticles to estimate the imprinting factor. Although hydrolysis of **1b** by NINP does not give saturation behavior, the data does fit to the Lineweaver-Burk plot (Figure S6) to give a \(k_{\text{cat}}\) of (7.2 \(\pm\) 1.3) \(\times\) 10\({}^{-3}\) s\({}^{-1}\) and a \(K_{\text{M}}\) of 350 \(\pm\) 15 \(\upmu\)M (Table 1, entry 2). Thus, an imprinting factor of 5.5 can be obtained if the \(K_{\text{M}}\) values of **NP-Zn** and NINP are used. The imprinting factor based on the catalytic efficiency (\(k_{\text{cat}}/K_{\text{M}}\)) is significantly higher, ca. 30. If the catalytic hydrolysis occurs in the active site of **NP-Zn**, as portrayed in Scheme 1, substrate selectivity should also be expected. To test this hypothesis, we studied the hydrolysis of **1c** and **1d**, the diphenyl carbonate derivative, with a _para_ and an _ortho_ methyl group on the phenyl rings. Because the template (**T**) has a _para_ nitro group on the phenyl rings, the resulting active site should be able to accommodate **1c** but exclude **1d** by the mismatched geometry. Indeed, the matched _para_-methyl substrate **1c** is reasonably active in its catalytic hydrolysis by **NP-Zn** (Figure 2b, solid diamond data points), whereas the mismatched **1d** with the _ortho_-methyl groups displays a negligible reactivity (Figure 2b, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Entry** & **Substrate** & **Catalyst** & \(k_{\text{cat}}\) (\(\times\)**10\({}^{-3}\) s\({}^{-1}\))** & \(K_{\text{M}}\) (\(\upmu\)M) & \(k_{\text{cat}}\)/\(K_{\text{M}}\) (M\({}^{-1}\)s\({}^{-1}\))** & \(k_{\text{cat}}\)/\(k_{\text{uncat}}\) \\ \hline
1 & **1b**\({}^{\text{a}}\) & **NP-Zn** & 39.5 \(\pm\) 0.6 & 64 \(\pm\) 3 & 610 & - \\
2 & **1b**\({}^{\text{a}}\) & NINP & 7.2 \(\pm\) 1.3 & 350 \(\pm\) 15 & 20 & - \\
3 & **1b**\({}^{\text{b}}\) & **NP-Zn** & 17.2 \(\pm\) 0.2 & 387 \(\pm\) 19 & 44 & - \\
4 & **1c**\({}^{\text{b}}\) & **NP-Zn** & 5.4 \(\pm\) 0.3 & 496 \(\pm\) 3 & 11 & - \\
5 & **1e**\({}^{\text{a,c}}\) & **NP-Zn** & 11.9 \(\pm\) 0.3 & 425 \(\pm\) 1 & 28 & 1.0 \(\times\) 10\({}^{6}\) \\ \hline \hline \end{tabular}  
* \({}^{\text{a}}\) Hydrolysis was performed in a 25 mm HEPES buffer (pH 7.0) at 25 \({}^{\circ}\)C. [cataly] = 5.0 \(\upmu\)M. \({}^{\text{b}}\) Hydrolysis was performed in a 25 mm HEPES buffer (pH 7.0) containing 25 vol % methanol at 25 \({}^{\circ}\)C. [**NP-Zn**] = 5.0 \(\upmu\)M. \({}^{\text{c}}\) The uncatalyzed rate constant (\(k_{\text{uncat}}\)) for the hydrolysis of diphenyl carbonate **1e** is 1.2 \(\times\) 10\({}^{-8}\) s\({}^{-1}\)[33].  
\end{table} 
Table 1: Michaelis–Menten parameters for the catalytic hydrolysis of aromatic carbonates by nanoparticle catalysts. Figure 2: (**a**) Dependence of initial velocity (\(V_{0}\)) on the substrate concentration for the hydrolysis of **1b** by **NP-Zn** and NINP in a 25 mM HEPES buffer (pH 7.0) at 25 \({}^{\circ}\)C and fitting of the **NP-Zn** data to the Michaelis-Menten model.