Detection of Cryptosporidium parvum in buffer and in complex matrix using PEMC sensors at 5 oocysts mL(-1)
1Department of Chemical and Biological Engineering, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA.
Abstract:
We show for the first time that a piezoelectric-excited millimeter-sized cantilever (PEMC) sensor can detect five Cryptosporidium parvum oocysts in 25% milk in PBS background in a flow format (1 mL min(-1)). To improve sensitivity, a secondary antibody (murine IgM) was used to confirm the attachment of oocysts to the sensor. PEMC sensor is a resonant-mode cantilever sensor whose resonant frequency decreases when target analyte binds to its surface. The sensor was functionalized with Protein G, and then immobilized with goat polyclonal IgG anti-C. parvum for oocysts detection. In the dynamic range of 50-10,000 oocysts mL(-1) the sensor response is characterized by a semi-log relationship between resonant frequency response and C. parvum oocysts concentration. In 25% milk background, binding kinetics was slower and total sensor response was lower (approximately 45%) than in water-like buffer.
Insights
A novel piezoelectric-excited millimeter-sized cantilever (PEMC) sensor successfully detected Cryptosporidium parvum oocysts in milk. This biosensor offers a sensitive method for detecting parasitic contamination in food and water samples.
Area of Science:
- Biosensing
- Parasitology
- Materials Science
Background:
- Cryptosporidium parvum is a significant waterborne protozoan parasite.
- Accurate detection of C. parvum oocysts is crucial for public health.
- Existing detection methods can be time-consuming or require specialized equipment.
Purpose of the Study:
- To develop and validate a highly sensitive biosensor for detecting C. parvum oocysts.
- To evaluate the performance of a piezoelectric-excited millimeter-sized cantilever (PEMC) sensor.
- To assess the sensor's efficacy in a complex matrix like milk.
Main Methods:
- Functionalization of the PEMC sensor with Protein G and goat polyclonal IgG anti-C. parvum.
- Detection of C. parvum oocysts in a flow format (1 mL/min).
- Utilizing a secondary antibody (murine IgM) to enhance detection specificity and sensitivity.
Main Results:
- The PEMC sensor demonstrated the ability to detect as few as five C. parvum oocysts.
- A semi-log relationship was observed between sensor response and oocyst concentration within the range of 50-10,000 oocysts/mL.
- Detection in a 25% milk background showed slower binding kinetics and reduced sensor response compared to buffer.
Conclusions:
- The PEMC sensor is a promising tool for the rapid and sensitive detection of C. parvum oocysts.
- The sensor's performance in complex matrices like milk warrants further investigation.
- This technology has potential applications in food safety and water quality monitoring.
