How immobilization Au chip with thiol group

Hello,
I have an untreated gold surface of cytiva Au sensor chip. I want to immobilize my ligand which contains thiol groups so do I have to make this immobilization outside or inside the instrument (Biacore T200)?

Hi,
Never done it my self. I would do it outside the instrument because of the interaction time and volume needed when injecting.
Question: when you mention ligand, is it a protein? Then I recommend a thiol immobilization on a CM5 sensor chip and not the AU surface. If the 'ligand' is a SH-alkane then use the AU surface.

kind regards
Arnoud

Ligand isn't a protein , it is thiol attached to PEG chain. I will follow your advice . Thank you!

So is it possible to immerse the full chip in a solvent containing my ligand modified with thiol groups?

Because as I read in the following quoted information that I should avoid contacting with some sides of the chip 

"Surface chemistry can be done prior or after docking the chip into the instrument. Modification prior to docking should be done with care. The side that interfaces with the opto-interface must be kept dry and free of dust. The sensor side should not be touched. The best way to apply solutions is in the corner of the sensor side."

www.sprpages.nl/sensor-chips-intro-2/biacore/au

Hi,

The side that interfaces with the opto-interface must be kept dry and free of dust. The detector side should not be touched. The best way to apply solutions is in the corner of the active side.

Therefore dipping the whole sensor in a solution is not an option. Apply the solution only to the active side by pipetting in the corner covering the whole sensor square.