A fiber optic nanoplasmonic biosensor for the sensitive detection of ampicillin and its analogs

Pallavi P. Chaudhari, Lai Kwan Chau, Yen Ta Tseng, Chun Jen Huang, Yuh Ling Chen

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


A novel optical immunosensor for the screening of ampicillin (Amp) residues has been developed. The biosensor is based on fiber optic particle plasmon resonance detection and uses an enhancement method called as fiber optic nanogold-linked immunosorbent assay (FONLISA) for the sensitive detection of antibiotics. A commercial antibody which had a higher affinity for ampicillin than for other β-lactam antibiotics was chosen. A surface competitive binding assay was used in which a fixed concentration of antibiotic-conjugated gold nanoparticles (AuNPs) competes with free unlabeled antibiotic molecules to measure the amount of binding with antibody molecules immobilized on an optical fiber. The synthesis of the 11-mercaptoundecanoic acid (MUA)-ampicillin conjugate facilitates the attachment of the Amp molecules to AuNPs via MUA which acts as a linker between them. This AuNP–Amp conjugate was then used for the detection of β-lactam antibiotics. The practical limit of detection obtained for Amp was 0.74 ppb (7.4 × 10−10 g/mL) which is lower than the recommended maximum residue limit (MRL) for β-lactams. The method also shows a wide linear range of 4 orders. Its applicability to the determination of ampicillin in spiked milk samples has been demonstrated with good recovery and reproducibility. [Figure not available: see fulltext.].

Original languageEnglish
Article number396
JournalMicrochimica Acta
Issue number7
StatePublished - 1 Jul 2020


  • Antibiotics
  • Biosensor
  • Fiber optic
  • Gold nanoparticle
  • Immunoassay
  • Nanoplasmonic
  • β-Lactam


Dive into the research topics of 'A fiber optic nanoplasmonic biosensor for the sensitive detection of ampicillin and its analogs'. Together they form a unique fingerprint.

Cite this