Text this: Fiber optic interferometer sensor for responsive hydrogel based heavy metal cation detection

 __   _     ______    _  __    _____     _  __  
| || | ||  /_   _//  | |/ //  |  ___||  | |/ // 
| '--' ||   -| ||-   | ' //   | ||__    | ' //  
| .--. ||   _| ||_   | . \\   | ||__    | . \\  
|_|| |_||  /_____//  |_|\_\\  |_____||  |_|\_\\ 
`-`  `-`   `-----`   `-` --`  `-----`   `-` --`