无法检查输入模式 - Razerpay与Codeigniter的集成

I was trying to integrate Razorpay payment gateway in Codeigniter by referring code and Demo from this website. While Integrating I found this

Unable to check <input pattern='^[a-zA-Z. 0-9\']{1,100}$'> because the pattern is not a valid regexp: invalid identity escape in regular expression

Is this a issue in case of security? If so, How can I solve it.

Thanks in advance.