How our sensors work

To get the best out of our biosensors, please remember: The sensors are fragile –handle with care and do not touch or knock the sensing tip. Once a sensor has been rehydrated, store in buffer at 2-8 C. Wet storage of sensor following rehydration is guaranteed for 5 days. Following rehydration do not attempt to re-dry the sensor. Keep exposure of sensor in the air to a minimum –preferably no more than 30s at a time as prolonged exposure to air can result in loss of sensitivity.

How to use our sensors

• Storage

Store in Fridge at 2-8 C before use.
Operation of sensor after use-by date is not guaranteed.


• Rehydration procedure

Prepare Buffer A: containing 10 mM NaPi buffer, pH 7.4, 100 mM NaCl, 1 mM MgCl2, 2 mM glycerol. Pour a suitable volume of Buffer A into rehydration pot, and immerse the tip of the sensor into the buffer. Leave for at least 10 min.


• Cycling

this will improve sensor sensitivity by up to 3 fold. Cycle the sensor from –500 mV to + 500 mV and back at a rate of 100 mV/s for 10 cycles. Then polarize to +500 mV for calibration.


• First calibration and sensor test –in vitro

Test against the specific analyte Place sensor and Ag/AgCl reference electrode in the bath, connect Ag/AgCl reference electrode and sensor to 2-electrode potentiostat and polarize to +500 mV. Allow sensor current to asymptote –Take zero reading. Expose the sensor to analyte.


• Checking interferences

Typically such as 10μM serotonin, 10μM dopamine and 100μM ascorbate acid


• Calibration -in situ

Regular calibration during an experiment is necessary to monitor for possible loss of sensor sensitivity after contact with tissue. Loss of sensor activity can be partially restored by cycling as described above. Sensors should be calibrated out of contact with tissue –as the tissue impedes free access of exogenous ACH or CHO to the sensor surface. If the tissue is in a flow chamber, the simplest procedure is to withdraw the sensor from the tissue and allow a test solution of ACH or CHO (e.g. 10 µM to flow through).
Note that calibration of the sensor in a physiological buffer may differ from that recorded in Buffer A due to the different ionic composition of the buffers. The sensor should always be calibrated in a saline of the composition use in the experiment with tissue.


• Post calibration



• More specific details for each sensor type please see Instruction for Use
  
  ATP
  ADO/INO/HYP
  ACH/CHO
  GLU
  LAC
  
  

Choosing the right sensor

Ø25 x 0.5mm – least damage of tissue; best for recording from very small structure

Ø50 x 0.5mm – most commonly used by our customers; ideal for brain slice recording, cultured cells and in vivo

Ø50 x 2mm – gives bigger signal; can be used for recording from bigger structures

matching reference sensors – please see starter kit page

DIY your own sensor holders

To DIY your own sensor holders, you will need a cable (thinner than a 1ml syringe), a 1ml syringe, a gold-plated pin (buy from Sarissa) and some superglue and soldering kit.

First, solder the pin onto one end of the cable and feed it through the syringe.

Superglue both ends to stabilized the cable. And done!