A highly sensitive surface acoustic wave sensor modified with molecularly imprinted hydrophilic PVDF for the selective amino acid detection

• Published in: Sensors and actuators. A. Physical. 2022-07, Vol.341, p.113525, Article 113525
• Main Authors: Prabakaran, K., Jandas, P.J., Luo, Jingting, Fu, Chen
• Format: Article
• Language: English
• Subjects: Adsorption; Amino acids; Ascorbic acid; Atomic force microscopy; Biosensor; Delay lines; Fourier transforms; Hydrophilicity; Imprinted polymers; Infrared analysis; Infrared spectroscopy; L-Tryptophan; Leucine; Molecular imprinting; Molecular imprinting polymer; Photolithography; Poly (vinylidene fluoride); Polyhydroxyethyl methacrylate; Polymerization; Receptors; Scanning electron microscopy; Selectivity; Sensors; Surface acoustic wave; Surface acoustic wave devices; Surface acoustic waves; Surface chemistry; Tryptophan; Tyrosine; Vinylidene; Water treatment
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2022.113525

Molecularly imprinted templates for L-Tryptophan sensor using hydrophilic poly (vinylidene fluoride) (PVDF) was fabricated through in-situ polymerization of 2-hydroxyethyl methacrylate (HEMA) within PVDF matrix. The work proposes a novel strategy for the integration of antifouling layer modification for water treatment technique into molecular imprinting polymer for surface acoustic wave (SAW) sensor fabrication and demonstrates their effective utilization in direct biological applications. The L-Tryptophan templates were carefully prepared on the delay line area of a SAW device prepared through photolithographic method internally. The imprinted template was qualitatively analysed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) to understand the bond formation and distribution of imprinted textures on the receptor surface. Quantitative measurements as the L-Tryptophan receptor was conducted through SAW analysis within range of concentration 0.5–150 ng/ml and the sensor responded linearly with the varying concentration. The limit of detection and limit of quantification calculated to be 0.2 and 0.6 ng/ml, respectively. The mechanism of adsorption was further studied using Langmuir, Freundlich and Redlich-Peterson adsorption isotherm. The MIP modified SAW sensor had high selectivity in the presence of structural analogues such as D- tryptophan, ascorbic acid, leucine and tyrosine. The hydrophilic PVDF coated MIP-SAW sensor exhibited relatively high imprinting factor towards L-tryptophan of about 9.34. Schematic diagram of SAW sensing setup [Display omitted] •Hydrophilic poly(vinylidene fluoride) (PVDF) film based MIP is developed via in situ polymerization technique.•The limit of detection and limit of quantification were determined as 0.2 ng/ml and 0.6 ng/ml respectively.•The experimental findings indexed with various theoretical adsorption models.•MIP system exhibited a good selectivity in the presence of structural analogues.