A pyroelectric-based system for sensing low abundant lactose molecules

A novel method for sensing low abundant lactose in small sample volumes is proposed. It is based on a pyroelectrodynamic jet (p-jet) system able to concentrate the lactose molecules onto a solid amine support for easy and rapid detection through a fluorescence measurement. The p-jet produces droplets with sub-picoliter volumes accumulated onto a microscale area of the solid support in order to reduce the diffusion limits typically occurring in standard well-based assays. A highly reproducible linear response for lactose was obtained between 2 pM/mu L and 10 pM/mu L. The great advantage of the technique is the ability to concentrate the molecules directly onto the solid support ready for the readout measurement by a standard fluorescence scanner. No time-consuming and expensive sample treatments are needed. The proposed method is rapid, suitable for repeated use providing a built-in quality assurance..