Warning: implode() [function.implode]: Invalid arguments passed in /

I get this error at the very footer of any pages

Theme: Nillpano
Plugin: business-directory-???

Warning: implode() [function.implode]: Invalid arguments passed in /home/teste/www/wp-content/themes/pano/footer.php on line 32

30 – <?php
31 – $nill_sliderpost = get_field(‘nill_pageslidercat’ , ‘option’);
32 – $nill_sliderposts = implode(‘,’,$nill_sliderpost);
33 – $nill_slidershow = get_field(‘nill_slidershowpost’ , ‘option’);
34 – ?>

Thanks

Eli.