Plugin settings checkbox

Question

I am creating catagory checkbox select.

My code to render the category checkbox is:

// CHECKBOX - Name: plugin_options[chkbox2]
function setting_chk2_fn() {

    $options = get_option('plugin_options');
    $categories = get_categories('orderby=name');  
    $wp_cats = array();  

    foreach( $categories as $category_list ) {  
        $wp_cats[$category_list->cat_ID] = $category_list->cat_name;  
    }  

    foreach( $wp_cats as $v ) {
        echo "<input type='checkbox' name='plugin_options[chkbox2]' value='{$options['chkbox2']}' />";
        echo $v;
        echo '<br>';
    }
}

All catagories are rendered properly but it is not saving in database. Thanks for reading