May i ask if your samples is in liquid form or powder form? Or you grow your samples on top of silicon wafer?

An Giang Nguyen what do you mean more exactly?

Khairani Hasuna Jaapar my samples are in liquid form. In literature I found that they used silicon wafer as a substrate, placed 10 uL of solution and dried it in the oven. The group that has SEM doesn't have silicon wafer so I want to use an aluminium one in the exact same manner.

I am not sure about aluminium and copper substrate. In our laboratory we have carbon tape/copper tape/aluminium tape/copper grid that we stick on top of sample holder.

I have seen a lot of nanoflower samples but it is quite direct in powder form. Sometimes i just drop the samples that is in liquid form on top of the carbon tape but sometimes we lost the samples as it will embedded/implanted inside the carbon tape. If we are lucky enough we will hardly find the samples morphology.

However you are saying about highly packed DNA nanoflower origami in liquid form. If most of the articles that you read can only see the DNA origami images by using TEM, then i will suggest you to try ask the technician if the SEM facilities have copper grid to view your samples using STEM detector. If the SEM facilities didn't have STEM detector, just drop your samples on top of the copper grid and try view using normal SEM so that you won't lost the samples but at the same time your samples will be as much as conductive as it can to go to high resolution to be view by the SEM instrument.

Otherwise just try to go with the copper/aluminium substrate that you mentioned with the exact same manner. I am just afraid if your SEM facilities cannot go to high resolution but who knows maybe you can see the nanoflower shape samples.

This is just my one percent suggestions based on my personal experience as a fesem technicians. I am also keep learning from samples.