Detect if a specific shortcode is being used in post_content. Returns a boolean.

detect_shortcode.php

<?php 
function hip_detect_shortcode( $shortcode = false ) {
	
	$shortcode_found = false;
	
	if( $shortcode && is_singular() ) {
    
    		global $post;
    		$pattern = get_shortcode_regex();
		
    		if( preg_match_all( '/'. $pattern .'/s', $post->post_content, $matches ) && array_key_exists( 2, $matches ) && in_array( $shortcode, $matches[2] ) ) {
			$shortcode_found = true;
		}
    	}
  	
  	return $shortcode_found;
}