Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers

Roberto De La Rica, Antoni Baldi, Cesar Fernandez-Sanchez, Hiroshi Matsui

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The risk of infectious diseases has compelled some industries to establish a zero-tolerance standard for the presence of microorganisms in a given sample. Here, we address this issue with a novel reverse-phase immunoassay on impedimetric transducers for the specific detection of extremely low numbers of pathogens (less than 10 cells). After simply spotting the sample onto the electrodes, physisorbed analytes were targeted with urease-labeled antibodies, and the urease on the pathogens hydrolyzed urea to ionic species with a concomitant decrease of the resistivity of the solution. By this methodology, the limit of detection (LOD) based on the 3 sigma criterion was 1 Escherichia coli cell with an assay time under 1 h. However, the precise number of cells present in highly diluted samples is uncertain, making it difficult to assess the final LOD of the sensor. We overcome this problem by using an atomic force microscope to deposit and image in situ the exact number cells on the transducer. After performing the immunoassay, a single E. coli cell was successfully detected without ambiguity in the number of cells even in the presence of a 10(4) excess of a competing microorganism, thus demonstrating the outstanding LOD and selectivity of the proposed reverse-phase immunoassay.
Original languageEnglish
Pages (from-to)7732-7736
Number of pages5
JournalAnalytical Chemistry
Volume81
Issue number18
Publication statusPublished - 15 Sep 2009

Fingerprint

immunoassay
pathogens
Urease
Pathogens
Microorganisms
Escherichia coli
Transducers
transducers
cells
Urea
Assays
Microscopes
Deposits
microorganisms
Electrodes
Antibodies
Sensors
Industry
infectious diseases
Escherichia

Keywords

  • reverse-phase
  • immunoassay
  • single-cell
  • pathogen detection
  • impedimetric transducers

Cite this

De La Rica, R., Baldi, A., Fernandez-Sanchez, C., & Matsui, H. (2009). Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers. Analytical Chemistry, 81(18), 7732-7736.
De La Rica, Roberto ; Baldi, Antoni ; Fernandez-Sanchez, Cesar ; Matsui, Hiroshi. / Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers. In: Analytical Chemistry. 2009 ; Vol. 81, No. 18. pp. 7732-7736.
@article{17ebe27c81324ac788eba2dcae3b16d3,
title = "Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers",
abstract = "The risk of infectious diseases has compelled some industries to establish a zero-tolerance standard for the presence of microorganisms in a given sample. Here, we address this issue with a novel reverse-phase immunoassay on impedimetric transducers for the specific detection of extremely low numbers of pathogens (less than 10 cells). After simply spotting the sample onto the electrodes, physisorbed analytes were targeted with urease-labeled antibodies, and the urease on the pathogens hydrolyzed urea to ionic species with a concomitant decrease of the resistivity of the solution. By this methodology, the limit of detection (LOD) based on the 3 sigma criterion was 1 Escherichia coli cell with an assay time under 1 h. However, the precise number of cells present in highly diluted samples is uncertain, making it difficult to assess the final LOD of the sensor. We overcome this problem by using an atomic force microscope to deposit and image in situ the exact number cells on the transducer. After performing the immunoassay, a single E. coli cell was successfully detected without ambiguity in the number of cells even in the presence of a 10(4) excess of a competing microorganism, thus demonstrating the outstanding LOD and selectivity of the proposed reverse-phase immunoassay.",
keywords = "reverse-phase , immunoassay, single-cell, pathogen detection, impedimetric transducers",
author = "{De La Rica}, Roberto and Antoni Baldi and Cesar Fernandez-Sanchez and Hiroshi Matsui",
year = "2009",
month = "9",
day = "15",
language = "English",
volume = "81",
pages = "7732--7736",
journal = "Analytical Chemistry",
issn = "0003-2700",
publisher = "American Chemical Society",
number = "18",

}

De La Rica, R, Baldi, A, Fernandez-Sanchez, C & Matsui, H 2009, 'Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers', Analytical Chemistry, vol. 81, no. 18, pp. 7732-7736.

Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers. / De La Rica, Roberto; Baldi, Antoni; Fernandez-Sanchez, Cesar; Matsui, Hiroshi.

In: Analytical Chemistry, Vol. 81, No. 18, 15.09.2009, p. 7732-7736.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers

AU - De La Rica, Roberto

AU - Baldi, Antoni

AU - Fernandez-Sanchez, Cesar

AU - Matsui, Hiroshi

PY - 2009/9/15

Y1 - 2009/9/15

N2 - The risk of infectious diseases has compelled some industries to establish a zero-tolerance standard for the presence of microorganisms in a given sample. Here, we address this issue with a novel reverse-phase immunoassay on impedimetric transducers for the specific detection of extremely low numbers of pathogens (less than 10 cells). After simply spotting the sample onto the electrodes, physisorbed analytes were targeted with urease-labeled antibodies, and the urease on the pathogens hydrolyzed urea to ionic species with a concomitant decrease of the resistivity of the solution. By this methodology, the limit of detection (LOD) based on the 3 sigma criterion was 1 Escherichia coli cell with an assay time under 1 h. However, the precise number of cells present in highly diluted samples is uncertain, making it difficult to assess the final LOD of the sensor. We overcome this problem by using an atomic force microscope to deposit and image in situ the exact number cells on the transducer. After performing the immunoassay, a single E. coli cell was successfully detected without ambiguity in the number of cells even in the presence of a 10(4) excess of a competing microorganism, thus demonstrating the outstanding LOD and selectivity of the proposed reverse-phase immunoassay.

AB - The risk of infectious diseases has compelled some industries to establish a zero-tolerance standard for the presence of microorganisms in a given sample. Here, we address this issue with a novel reverse-phase immunoassay on impedimetric transducers for the specific detection of extremely low numbers of pathogens (less than 10 cells). After simply spotting the sample onto the electrodes, physisorbed analytes were targeted with urease-labeled antibodies, and the urease on the pathogens hydrolyzed urea to ionic species with a concomitant decrease of the resistivity of the solution. By this methodology, the limit of detection (LOD) based on the 3 sigma criterion was 1 Escherichia coli cell with an assay time under 1 h. However, the precise number of cells present in highly diluted samples is uncertain, making it difficult to assess the final LOD of the sensor. We overcome this problem by using an atomic force microscope to deposit and image in situ the exact number cells on the transducer. After performing the immunoassay, a single E. coli cell was successfully detected without ambiguity in the number of cells even in the presence of a 10(4) excess of a competing microorganism, thus demonstrating the outstanding LOD and selectivity of the proposed reverse-phase immunoassay.

KW - reverse-phase

KW - immunoassay

KW - single-cell

KW - pathogen detection

KW - impedimetric transducers

UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2888025/

M3 - Article

VL - 81

SP - 7732

EP - 7736

JO - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

IS - 18

ER -

De La Rica R, Baldi A, Fernandez-Sanchez C, Matsui H. Single-cell pathogen detection with a reverse-phase immunoassay on impedimetric transducers. Analytical Chemistry. 2009 Sep 15;81(18):7732-7736.