Sounds like your curriculum needs updating to incorporate the existence of these tools. As I’m sure you know, kids - especially smart ones - are going to look for the lazy solution. An AI-detection arms race is wasting time and energy, plus mostly exercising the wrong skills.

AVID could be a resource for teaching ethics and responsible use of AI. https://avidopenaccess.org/resource/ai-and-the-4-cs-critical-thinking/