# Molecularly-Imprinted SERS: A Potential Method for Bioanalysis
## 4 Molecularly-Imprinted SERS Methods
### Two Step MIP-SERS  
In two-stage MIP-SERS, MIP is separated from metal nanoparticles which are used as substrates in SERS analysis. [PERSON] et al., analyzed the content of bitertanol, a triazide fungicide compound, in vegetable (cucumber) and fruit (peach) samples. MIP is used in this study to reduce interference from impurities that can interfere with the analysis results with SERS. In the manufacture of MIP, a dummy template is used, triadimefen, to prevent template leakage. It is expected to obtain better selectivity than using a template in the form of the analyte to be analyzed. MIP was packaged as a sorbent in an SPE cartridge during the analysis. The overall analysis time is 15 min. The developed method shows the same performance when compared to the previous methods (LC-MS, GC-MS, and HPLC-DAD), with a better analysis time [27].  
[PERSON] et al. also conducted a similar study to develop other triazine fungicide analysis methods, prometryn and simetryn, on rice and wheat samples. However, in this study, the same template was used with the analyte to be determined. This study's MIP-SERS analysis method was then compared with several previous analytical methods (GC-NPD, LC-DAD, MIP-SPE-HPLC, Fluorescence, AgNP-SERS, GC-TSD, CNT-Au-SERS). The results show that the newly developed Au-MIP-SERS method has the same performance as the previous method; even some parameters show better results [118].  
The pesticide residue, chlorpyrifos, was also developed using the two-step MIP-SERS method. In this study, AgNPs were not only used as a substrate in SERS analysis but were also developed to be used as a colorimetric detection method for the same compound. The results showed that that method could be used to separate chlorpyrifos from apple juice samples. The AgNPs-colorimetric method could be used to detect chlorpyrifos in samples [136]. The analysis of herbicide residues (2,4-dichlorophenoxyoxyacetic acid) in milk was developed by the two-step MIP-SERS method. MIP is then packaged in an SPE cartridge and was used to separate the residue of 2,4-dichlorophenoxyoxyacetic acid. AgNPs as a substrate for SERS were synthesized separately using sodium citrate as a reducing agent. The analysis time required is quite fast, only about 10 min. The resulting analytical method is sensitive for detecting residues in dairy products [137].  
The combination of MIP-SPE and SERS was also analyzed for thiabendazole in apple juice. The analysis of thiabendazole was carried out in two stages. MIP is first synthesized and then used as an adsorbent on the SPE cartridge. AgNPs were synthesized from silver nitrate with trisodium citrate as a reducing agent.The total analysis time for thiabendazole analysis using MIP-SPE and SERS detection was 23 min. This analysis time is much faster than other traditional detection methods, which require complicated sample preparation [138]. The same analytical method was also developed to analyze atrazine in apple juice samples. This method uses AuNPs as substrate for detection with SERS. The results showed that this method can also be used to detect atrazine in other types of samples [139].