Spatially Controlled Monolayers for Electrically Switchable Biomolecule Detection

The development of biosensors that are low-waste, highly stable, and possess an ability to be interchanged between capturing and non-capturing configurations is promising for the biodetector field. Stable packing and attachment of the sensor, the ability to create an interchangeable detecting probe of interest relatively easily, and dynamic control of the probe via a reversible bias can provide for that. With the set goals to control all those properties, DNA-dendron conjugate molecules were designed, synthesized in solution, purified, and utilized to make self-assembled monolayers of single-stranded DNA on gold. To be able to manipulate the conjugates’ sensing qualities in the described manners, generation 4 (G4) polyamidoamine dendrimers were conjugated to ssDNA oligomers (18 bases) in a one-to-one ratio and functionalized to provide multiple thiol groups for possible surface assembly. DNA-dendron successful conjugation and their purification were confirmed by using gel electrophoresis. The height profiles and dynamic switchability were tested by utilizing atomic force microscopy. The conjugates’ attachment, packing density, and sensing ability were all measured from surface plasmon resonance experiments. The results outlined in this study demonstrate the potential of these novel DNA-dendron conjugates to advance the biosensors field and introduce a new way of thinking about the manufacturing of DNA monolayers on gold substrates