Selective Amplification of Plasmonic Sensor Signal for Cortisol Detection Using Gold Nanoparticles

Abstract

Herein, gold nanoparticles (AuNP)-modified cortisol-imprinted (AuNP-MIP) plasmonic sensor was developed for signal amplification and real-time cortisol determination in both aqueous and complex solutions. Firstly, the sensor surfaces were modified with 3-(trimethoxylyl)propyl methacrylate and then pre-complex was prepared using the functional monomer N-methacryloyl-L-histidine methyl ester. The monomer solution was made ready for polymerization by adding 2-hydroxyethyl methacrylate to ethylene glycol dimethacrylate. In order to confirm the signal enhancing effect of AuNP, only cortisol-imprinted (MIP) plasmonic sensor was prepared without AuNP. To determine the selectivity efficiency of the imprinting process, the non-imprinted (AuNP-NIP) plasmonic sensor was also prepared without cortisol. The characterization studies of the sensors were performed with atomic force microscopy and contact angle measurements. The kinetic analysis of the AuNP-MIP plasmonic sensor exhibited a high correlation coefficient (R2 = 0.97) for a wide range (0.01–100 ppb) with a low detection limit (0.0087 ppb) for cortisol detection. Moreover, the high imprinting efficiency (k′ = 9.67) of the AuNP-MIP plasmonic sensor was determined by comparison with the AuNP-NIP plasmonic sensor. All kinetic results were validated and confirmed by HPLC.

Development of a Plasmonic Sensor for a Chemotherapeutic Agent Cabazitaxel

“…During the process, the sessile drop method obtained the contact angle values, and the wettability was measured by dropping water on the surfaces. After dropping water into three different regions, images were taken in each region, and contact angles were determined …”

“…After dropping water into three different regions, images were taken in each region, and contact angles were determined. 30 …”

Nanomaterials for Cortisol Sensing

“…Yılmaz and co-workers developed a plasmonic sensor based on gold nanoparticles for the real-time determination of cortisol in complex aqueous solutions [ 56 ]. The sensor surfaces were modified with propyl 3-(trimethoxyl)methacrylate, and then a precomplex was prepared using the functional monomer N -methacryloyl-L-histidine methyl ester, and then 2-hydroxyethyl methacrylate was added to the monomer solution to ethylene glycol dimethacrylate, and polymerization was initiated.…”

Theoretical insights into the compatibility of template-monomer-crosslinker-solvent for cortisol molecularly imprinted polymer pre-polymerization

“…16 Several studies on MIP-based cortisol sensors have been published. 15,[17][18][19] In the literature, though based on trial and error, cortisol MIPs were investigated with the functional monomers in the presence of different solvents at a ratio (cortisol/monomer) 1 : 3 (11 functional monomers investigated), 20 1 : 4 (1 functional monomer investigated), 21,22 1 : 6 (1 functional monomer investigated), 23 1 : 10 (1 functional monomer investigated). 24 Many experimental investigations have been performed on cortisol MIPs, but the optimization of the functional monomers has been through trial and error.…”