Detecting Bacterial Contamination Using Magneto-fluorescent Nanosensors

Begin by adding magneto-fluorescent nanosensors to the bacterial samples. These nanoparticles contain bacteria-specific antibodies and a fluorescent dye.

Incubate to allow interaction with bacteria, causing detectable changes in the magnetic properties of the solution.

Include a baseline nanosensor solution without bacteria as a control.

Transfer each solution to a magnetic relaxometer, where a constant magnetic field aligns the magnetic particles within the sample.

Apply a brief pulse to disrupt alignment temporarily.

The relaxometer measures how quickly the particles return to their original state, known as the T2 relaxation time.

Nanosensors clustering around bacteria increases T2 compared to the control, enabling quantification even at low bacterial concentrations.

Conversely, higher bacterial concentrations decrease nanosensor clustering, affecting T2 values.

For accurate quantification, perform fluorescence measurement.

Accordingly, centrifuge to isolate bacteria and bound nanosensors.

Resuspend the pellet for fluorescence measurement.

Upon excitation, the fluorescent nanosensors emit light, aiding in bacterial measurement.