Highly regenerable and storageable all-chemical based PEG-immunosensor chip for SPR detection of ppt levels of fragrant compounds from beverage samples

K. Vengatajalabathy Gobi, Kiyoshi Matsumoto, Kiyoshi Toko, Norio Miura

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

Simple, automated and cost-effective sensor systems intended for detection of low-molecular-weight (LMW) fragrant compounds are indispensable at automated, bottle-filling production lines of food and beverage industries. Here, we report our investigations on the development of a highly regenerable and storageable surface plasmon resonance (SPR)-based biosensor for detection of trace amounts of benzaldehyde (BZ), a characteristic fragrant compound of peach products. The sensing surface was fabricated by self-assembling of long-chain polyethyleneglycol(PEG)-dialkanethiols on thin Au-films and by followed covalent-binding of a BZ analog on the self-assembly of PEG-dialkanethiols. The all-chemical based BZ-bound PEG-monolayer chip shows specific binding affinity toward anti-BZ antibody (BZ-Ab). The principle of indirect competitive immunoassay, promising highly sensitive and consistent detection of small molecular analytes, has been applied, wherein immunospecific binding of BZ-Ab onto the BZ-bound sensor surface is inhibited by analyte BZ present in test sample. The immunosensor exhibited excellent sensitivity for BZ detection over a wide concentration range of 0.1-80 ng/ml (ppb). The BZ-bound monolayer surface was highly regenerable and storageable for repeated use of a same sensor chip. The assay reproducibility was proved through sequential multiple analysis of the same sensor chip for more than 50 regeneration cycles. Sensitivity was enhanced further by an add-on strategy involving anti-(rabbit IgG)-functionalized Au nanoparticles (nAu-Ab), with which the sensor-signal is enhanced by about 15-18 times and the amount of BZ-Ab antibody required for an analysis could be reduced to one-tenth. With the enhancement technique, detection of as low as 7 pg/ml (ppt) BZ directly from beverage samples has been demonstrated.

Original languageEnglish
Pages (from-to)225-233
Number of pages9
JournalSensing and Instrumentation for Food Quality and Safety
Volume2
Issue number4
DOIs
Publication statusPublished - 2008

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Safety, Risk, Reliability and Quality
  • Industrial and Manufacturing Engineering

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