Can not decode data from serial port arduino send to mqtt server mosquitto

Question

I'm used ESP8266 receive data from atmega328pb via Serial and send these data to my MQTT broker (mosquitto). From server side I use NodeJS receive buffer but can not convert these data to string.

Sample buffer:
<Buffer 2b a1 71 2f c5 2b c2 d0 dc ec 3a 04 8c 62 4a 05 0d 0a>

Convert to Json:
{"type":"Buffer","data":[43,161,113,47,197,43,194,208,220,236,58,4,140,98,74,5,13,10]}

Convert to String uft8:
+�q/�+����:�bJ

My default text: 0100001100

How to fix this? Thank you.