# Molecularly-Imprinted SERS: A Potential Method for Bioanalysis
## 4 Molecularly-Imprinted SERS Methods
### One Step MIP-SERS
After the polymerization was complete, the rigid polymer was grounded. AgNPs were formed by add a reductor (Sodium borohydride) to the MIP powder. The recovery of this MIP-SERS method was calculated at 92.2% to 103.8%. According to spike sample, this method has a better recovery and relative standard deviation than HPLC methods. This method has a better limit of detection than HPLC methods [141]. The combination of magnetic core-shell SERS substrate was developed for antibiotics detection in water sample. Fe\({}_{3}\)O\({}_{4}\)@Ag composites was selected as a SERS substrate. In the end, the composites was then modified with dopamine to synthesize Fe\({}_{3}\)O\({}_{4}\)/Ag/MIP. Fe\({}_{3}\)O\({}_{4}\) nanoparticles were synthesized by hydrothermal reaction of dopamine and and modified with amino. Enrofloxacin hydrochloride was chosen as a template. Dopamine was selected as a functional monomer and crosslinkers. This material was synthesize by pDA polymerization. This method has better performance and limit detection, compared to another method of synthesis [142]. The detection of trace-level antibiotic was developed by using a novel composite material, AgP/MIM. Ag/GO (graphene-oxide argument) composite was used as a SERS substrate. To apply into practical sample detection, molecular imprinting technique was also introduced to improve the selectivity of the methods. Enrofloxacin hydrochloride was used as a template. AgNPs was synthesize by bottom up using silver nitrate as a precursor and ascorbic acid as a reductor. Ag/GO composite was synthesized by adding AgNPs into GO dispersion. The AgP/MIM was synthesize by step two precipitation polymerization at two different temperature. This method has better detection of limit and detection time, if we compared it to previous method [143]. Ag@MIPs hybrid was used in lysozyme analysis. Ag@MIPs hybrids was fabricated based on core-shell structure. Ag microsphere was synthesized by using ascorbic acid as a reductor. Ag microsphere and a mixture of MIP component were stirred. The lowest detection of limit concentration is 5 ng mL\({}^{-1}\). Ag@MIPs hydrid has better performance as a SERS substrate, comparing to Ag microsphere itself. This method can develop into a promising detection method for biomolecules, pathogens and living cells [144]. Ag@MIP hybrid was also used for p-nitroaniline in aqueous environment. The results show that this material can be used as a SERS substrate. The obtained Ag@MIP exhibit good limit of detection, \(10^{-12}\) M. Ag@MIP give better signal enhancement in SERS analysis than Ag nanoparticle itself [145]. Another application of MIP-SERS method is analysis of PAHs (polycyclic aromatic hydrocarbons). Au@MIPs was used as a SERS substrate. The Au@MIPs was fabricated by two-step procedure. Pyrene and fluoranthene, were used as a template. The combination of AuNPs and MIP solved each material's main limitation [146]. The detection of doxacillin in pig serum were found to be more sensitive by using combination of MMIP (magnetic molecularly imprinted polymer) with SERS. The limit of detection was 7.8 pmol. The cloxacillin recoveries were found to be more 80%. This method can be used routinely to screen antibiotic residues in food products [147].