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Updated: Apr 22, 2026
Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes
Published on: January 10, 2017
Carbon-Mercaptooctadecane/Carboxylated Multi-walled Carbon Nanotubes Composite Based Genosensor for Detection of
Sandip K Dash1, Minakshi Sharma2, Shashi Khare3
1CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007 India.
Abstract:
Human brain bacterial meningitis is a life-threatening disease mainly caused by Neisseria meningitidis, lead to several complications including damage of brain or even death. The present available methods for diagnosis of meningitis have one or more limitations. A rmpM gene based genosensor was fabricated by immobilizing 5'-amino modified 19-mer single stranded DNA probe onto carbon-mercaptooctadecane/carboxylated multi-walled carbon nanotubes composite electrode and hybridized with 2.5-40 ng/6 μL of single stranded genomic DNA (ssG-DNA) of N. meningitidis from cerebrospinal fluid (CSF) of the suspected meningitis patients. The electrochemical response was measured by using cyclic voltammetry and differential pulse voltammetry (DPV) using 1 mM methylene blue as redox indicator in 30 min (including a response time of 1 min) at 25 °C. The sensitivity of the genosensor was 3.762 (μA/cm(2))/ng and limit of detection was 2 ng of ssG-DNA of N. meningitidis with DPV. The genosensor has specificity only to N. meningitidis and does not hybridize with the genomic DNA of any other possible pathogen in human CSF. The immobilization of the probe and hybridization of the ssG-DNA were characterized by using electrochemical impedance in presence of 5 mM potassium ferricyanide and scanning electron microscopy. The genosensor loses only 12 % of its original DPV current on storage at 4 °C for 6 months. Carbon composite based electrochemical array can be constructed to detect multiple bacterial meningitis suspected patient CSF samples during an outbreak of the disease.
Insights
A novel genosensor detects Neisseria meningitidis, the cause of bacterial meningitis, using its rmpM gene in cerebrospinal fluid. This rapid and specific diagnostic tool offers high sensitivity and stability for improved meningitis detection.
Area of Science:
- Biosensor Technology
- Molecular Diagnostics
- Neuroscience
Background:
- Bacterial meningitis, primarily caused by Neisseria meningitidis, is a severe condition with significant mortality and morbidity.
- Current diagnostic methods for meningitis present limitations, necessitating the development of more effective approaches.
Purpose of the Study:
- To develop and characterize a novel genosensor for the specific and sensitive detection of Neisseria meningitidis DNA.
- To evaluate the genosensor's performance using clinical samples (cerebrospinal fluid) from suspected meningitis patients.
Main Methods:
- Fabrication of a genosensor by immobilizing a DNA probe targeting the rmpM gene of N. meningitidis onto a carbon nanotube composite electrode.
- Electrochemical detection using cyclic voltammetry and differential pulse voltammetry (DPV) with methylene blue as a redox indicator.
- Characterization of probe immobilization and DNA hybridization using electrochemical impedance spectroscopy and scanning electron microscopy.
Main Results:
- The genosensor demonstrated high sensitivity with a limit of detection of 2 ng of N. meningitidis genomic DNA.
- The developed genosensor exhibited excellent specificity, detecting only N. meningitidis without cross-reactivity with other pathogens.
- The genosensor maintained significant performance after long-term storage, losing only 12% of its current over 6 months at 4°C.
Conclusions:
- The rmpM gene-based genosensor provides a promising, rapid, and specific diagnostic tool for bacterial meningitis caused by Neisseria meningitidis.
- The developed electrochemical array holds potential for simultaneous detection of multiple pathogens in cerebrospinal fluid during outbreaks.
