Multianalyte pin-printed biosensor arrays based on protein-doped xerogels

We report the first biosensor arrays based on pin printing protein-doped xerogels. The individual biosensor elements are on the order of 100 mum in diameter. Arrays are formed (1) onto a planar substrate that is excited by an external source (laser) or (2) directly on the face of a light-emitting diode. We illustrate the potential of our approach by fabricating, testing, and characterizing four types of pin-printed biosensor arrays (PPBSA) for the simultaneous detection of glucose and O-2. The analytically reliable operating ranges for the PPBSAs are 0.1-10 mM for glucose and 0.1-100% for O-2. The PPBSAs exhibit short- and long-term reproducibilities of no worse than 4 and 8%, respectively. The overall array-to-array response reproducibilities are less than or equal to 12%. These results demonstrate for the first time the combination sol-gel processing and pin printing methods as a way to rapidly form ensembles of integrated, reusable, and stable biosensor arrays for simultaneous multianalyte detection.