Label-free glucose sensing with temperature modulation

• Very small amount of glucose concentration up to sub-millimolar range was detected.
• The local Joule heating changed the electrical conductivity of glucose solution.
• The solution with lower concentration showed further conductivity enhancement.
• The concentration was distinguished based on the electrical conductivity variation.

Label-free detection of glucose molar concentration was carefully studied with a device which was designed to modulate temperature in a local area by Joule heating from room temperature to human body temperature. Very small amount of glucose concentration up to sub-millimolar range was detected based on the glucose concentration dependent electrical resistance change with the temperature modulation since it allowed more electrical conductivity enhancement for lower glucose concentration.