Chart вывод графика

lineChartData = JSON.parse(data);
var myLineChart = new Chart(ctx, {
    type: 'line',
    data: lineChartData
 });
 var ctx = document.getElementById('myChart').getContext('2d');
 window.myLineChart = new Chart(ctx).Line(lineChartData, {responsive: true});

почему пишет

Uncaught TypeError: Cannot create property 'datasets' on string '[{"labels":["Январь","Февраль"],"datasets":{"label":"Продано","borderColor":"#000","backgroundColor":"transparent","pointBorderColor":"#000","pointBackgroundColor":"#000","pointRadius":"5","pointHoverRadius":"10","data":["7750.00","15345.00"]}}]'

данные вывожу из php

$arrDatasets = array('label' => "Продано",'borderColor' => "#000", 'backgroundColor' => "transparent", 'pointBorderColor' => "#000", 'pointBackgroundColor' => "#000", 'pointRadius' => "5", 'pointHoverRadius' => "10",'data'=>$data);
            $arrReturn = array(array('labels' => $months, 'datasets' => $arrDatasets));
            print (json_encode($arrReturn, JSON_UNESCAPED_UNICODE));