Application of nanotechnology in biosensor

CourseCurrent topics in biochemistry

Instructors: Dr. I.M. Santha Dr. A. Sachdev Dr. A. Dahuja

Presented by: Om Prakash Gupta 9817, Ph.D,

Science of using or producing objects

– that are nanometers in size (nano = 1 billionth)

– the ability to manipulate and control those materials in a useful way

– for industrial applications in the medical, chemical, materials, electronics, sensing and other fields

What is Nanotechnology?

A biosensor is an analytical device which converts a biological response into an electrical signal.

Biosensor

Two element

Powerful recognition capability of biomolecules

Transducer element to translate the interaction of biomolecules into a detectable signal

- nanotechnology approaches are offering a large series of nanoparticles (NPs) with special interest for biosensing systems- NPs are gaining interest in biosensing applications due to the size and shape dependent physical, chemical and electrochemical properties.

Micro/Nanobiosensor fastinexpensivesimple to use

very efficientportablemulti-analyte, high throughput

Why only nanotechnology in Biosensor?

Standard Procedures Microbiological culture proceduresMicroscopyBiochemical assaysImmunoassaysPCR

Disadvantages Time consuming and/ornon-specific and/orcost-intensive and/ornon-portable and/ortrained personnel

Nanoparticles•Metal nanoparticles•Magnetic nanoparticles•Nanowires•Nanofiber•Nanoprobes•CNT•Nanoscopic gold tube•Nanocrystalline silicon•QDs

-The range of the used NPs depends on the types of sample and biomolecules being analyzed

1. Novel nanomaterials adaptable to food analysis(limited sample preparation)

2. Novel detection mechanisms based on the nanoscale(fundamental studies)

3. Novel integration mechanisms of transducer and bio-element

4. Lab on chip

5. etc.

Suggested 5 areas for Nanobiosensors

NPs based detection techniques

Fluorescence based biosensor: use of QD

QDs are nanometer-scale semiconductor crystals composed of groups II–VI or III–V elements

When a photon of visible light hits such a particles, some of their electrons are excited into higher energy states

Returning to ground state a photon of frequency is emitted, fluorescence is measured

Superiority of QDs over conventional dyes

o excitation spectrumo emission spectrumo Photostabilityo Decay lifetime

Strategy for attaching bio-molecules to QDs

Design of QD based DNA nanosensor

Application of QD based optical nanosensor

1. In gene technology: DNA, RNA hybridization, gene expression, RNAi

2. Intracellular protein labeling

3. Cell tracking

4. Pathogen and toxin detection

5. In vivo animal imaging

Jamieson T., et al., Biomaterials , 28 (2007) 4717–4732

Fluorescence quenching

Gold nanocrystals, universal fluorescence quenchers

Maxwell et al., (2002)

Inductively coupled plasma mass spectrometry

(ICPMS) is used to detect and quantify nanoparticles

AuNPs modified with anti-mouse IgG have been used to trace oligonucleotides carrying a c-myc peptide

ICPMS-linked DNA assay may havesignificant potential as an importantnonradioactive DNA detection

Merkoci et al., 2005

Working of ICP-MS

Allabashi R. et al., 2009

Potentiometric analysis

- Potentiometry is the field of electroanalytical chemistry in which potential is measured under the conditions of no current flow. The measured potential may then be used to determine the analytical quantity of interest, generally the concentration

- potentiometry has been used for ultrasensitive nanoparticle-based detection of protein interactions

- A silver ion-selective microelectrode (ISE) is used to detect silver ions oxidatively released from silver enlarged gold nanoparticle labels (connected with anti-mouse IgG antibody) in a sandwich immunoassay

(Chumbimuni-Torres et al., 2006)

Magnetic sensor

- Superparamagnetic iron oxide nanoparticles to identify Mycobacterium through magnetic relaxation

- The principle of detection of this nanosensor is based on its ability to switch between a disperse and clustered state upon target interaction, with a concomitant change in the spin–spin relaxation time (T2) of the solution’s water protons.

Kaittanis et al., 2007

Use of nano-technology and Nano-biosensor in food industry

Sozer and Kokini, 2009

Nano-biosensor in food industry

- the main aim of nanosensors in food spoilage industry is to reduce the timefor pathogen detection from days to hours or even minutes

- An array of thousands of nanoparticles designed to fluoresce in different colors on contact with food pathogens

*Digital transform spectrometer (DTS) uses microelectromechanical sys- tems technology

* Nanocantilever

Nano-biosensor in environmental science:

Enzyme engineering for biosensor development: Pesticide detection

- Acetylcholinesterase (AChE) is irreversively inhibited by organophosphate group pesticide

- Knowledge exploited for inhibitor biosensor devlopment

- Taken wild type AChe enzyme from Drosophila, did several SDM to decrease the Ki value at active site

The enzyme is immobilized into microporous-activated conductive carbon

The principle is based on electrochemical biosensor

Thank You