如何用$ nin实现搜索

I'm using this $nin query for $regex search but it does not work:

first_name: { $nin: [ "/^rahul/i", "/^Bhosale/i" ] }

With this query execution, I was unable to find a result without "rahul" or "bhosale" but when I hit this query like below

first_name: { $nin: [ /^rahul/i, /^Bhosale/i ] }

it works fine.

when I pass an array to find() I think it takes the backslash with double quotes that why it was unable to find a result.

How can I solve this problem?