Mold from leak in closet - possible to DIY repair?

Hi all,

I live in an apartment in NYC and recently discovered a leak in the closet where our washer/dryer is stored. It was brought to my attention when I noticed black mold (I think it’s mold?) forming. It’s a stacked unit, and the leak was coming from the tubing of the dryer which had come loose. I’m not sure how long this was going on for, but I’m guessing at least a month, with about 2-3 loads of laundry happening per week. The area with visible mold is a little less than 1 foot by 1 foot.

We had someone come to look at it today who used some device and determined that the wooden floorboard was saturated with water. He said he would need to apply an antimicrobial spray for $350 and that we would need to use a commercial dryer to dry it out for about $30/ day, and only then could he assess the extent of the damage. I’m a bit concerned about the chemicals in the antimicrobial (it’s called ProKure) because I’m currently 6 months pregnant. It also seemed like a lot of money for such a small area. Is there any chance my husband could take care of part of the work himself? I’m imagining the floor boards will need to be removed... is there any way I can post a photo here?

Thanks so much,
Nancy